Free Calculator Widgets for Your Website

Monthly instalment, total interest and total repayment for any loan.

Payment, total interest and payoff date for any loan, with monthly, biweekly or weekly payments.

Monthly mortgage payment with property tax, insurance, HOA dues and PMI broken out.

Future value of a lump sum and monthly contributions at any compounding frequency.

Estimated value of a monthly SIP, with an optional yearly step-up.

Simple interest and total amount for a period in years, months or days.

Fixed deposit maturity value, or the monthly or quarterly interest payout.

Projected retirement savings against what an inflation-linked income needs.

Australian net pay per week, fortnight or month on 2026-27 ATO rates, with Medicare, HELP and super.

Irish PAYE net pay for 2026 after income tax, USC and Class A PRSI, incl. the October PRSI rise.

How much to save each month to reach a goal by a date, counting interest.

UK salary after income tax, National Insurance, pension and student loans for 2026-27, incl. Scotland.

What something will cost in future, and what today's cash will be worth, at a rate you choose.

Compound annual growth rate between a starting and an ending value.

Return on investment as a percentage, plus the annualised figure when you add the period.

How long a card balance takes to clear and what it costs, or the payment to clear it by a date.

Avalanche versus snowball for up to five debts: months to debt-free and total interest.

German gross-to-net pay for 2026, tax class I: income tax, Soli, church tax and social insurance.

Take-home pay per paycheck after 2026 federal income tax, Social Security, Medicare, 401(k) and HSA.

The home price an income supports under the 28/36 debt-to-income rule.

Compare net worth after renting or buying over the years you plan to stay.

Gross and net rental yield after vacancy and running costs.

Capitalization rate from income and price, or the value at a target cap rate.

Down payment, loan amount, LTV and total cash needed to buy a home.

Maximum home-loan EMI and loan amount from net income using the FOIR method.

Total floor area of up to six rectangles, circles and triangles in sq ft and square metres.

Paint needed for a room after doors and windows, rounded up to real can sizes.

How much sooner a home loan ends, and how much interest disappears, with extra or lump-sum payments.

SDLT on a home in England or Northern Ireland: first-time buyer, additional and non-resident rates.

Scottish LBTT on a home purchase with first-time buyer relief and the 8% Additional Dwelling Supplement.

New payment, monthly saving, break-even month and lifetime interest when a mortgage is refinanced.

Welsh LTT on a residential purchase at the main rates or the separate higher residential rates.

Monthly and yearly cash flow, NOI and DSCR for a rental after expenses and the mortgage payment.

NSW, VIC or QLD transfer duty for home buyers, first home buyers and investors, plus foreign surcharges.

Year-one cash-on-cash return on the money actually put into a property, with an optional cost breakdown.

Council tax bands, values and ratios to Band D for England, Scotland and Wales, priced from your council.

Project a home's future value at a growth rate, or find the yearly rate between two sale prices.

Fix-and-flip profit, ROI and annualised ROI with hard-money financing, plus the 70% rule offer.

Rent you can afford at 30% of gross income, a 25-35% range and what is left after rent and debts.

Price per square foot or square metre for up to three listings side by side, or a price from a rate.

Interest-only cost of a construction loan drawn in stages, then the payment after it converts.

Profit, gross margin and markup from cost and price - or the price for a target margin.

Selling price from cost plus markup, or work back to the cost or the markup you applied.

Sale price and savings, including stacked discounts and sales tax on the reduced price.

Units and revenue needed to cover fixed costs, plus the sales needed for a profit target.

Add or remove Indian GST at the rate you choose, split into CGST + SGST or IGST.

Add VAT to a net price or extract it from a gross price, at a UK rate or any rate you type.

US-style sales tax from the state and local rates you enter, or the tax hidden in a tax-inclusive total.

Tip, total and each person's share of a bill, with an option to round shares up.

What you receive after a percentage-plus-fixed processing fee, or what to charge to receive a set amount.

Minimum hourly and day rate from the income you want, your costs, tax and billable hours.

Standard and reduced VAT rates of all 27 EU Member States, dated and sourced, with a net/gross calculator.

Pick a state and get its official statewide sales tax rate, the tax on a price and the total - or reverse it.

Add or remove Australian 10% GST, or total an invoice's taxable and GST-free lines with the ATO checklist.

Profit, margin, effective hourly rate and budget burn for a fixed-fee or hourly client project.

Billable utilization against available hours, the gap to target and the revenue it represents.

Three-point PERT estimates for up to six tasks: expected time, standard deviation and 68% and 95% ranges.

Profit per order after cost, shipping, payment and marketplace fees, ads and returns - plus break-even ROAS.

Average order value, orders needed for a revenue goal, and the payoff of a higher basket size.

How many more units a discount must sell to keep the same gross profit, with a 5-25% comparison table.

Return on ad spend as a multiple and a percentage, with break-even ROAS from your margin.

Solve CPM, campaign cost or impressions from the other two.

Cost per click plus CTR, CPM, conversion rate and CPA from one campaign's totals.

Conversion rate from visitors and conversions, with an optional A/B comparison and z-test.

Social media engagement rate by followers and by reach, for one post or several.

Marketing efficiency ratio from total revenue and spend, new-customer aMER and a spend ceiling.

Network, broadcast, host range, masks and host count for any IPv4 CIDR, with subnet splitting.

Cost per request, day and month for any LLM API from tokens or words and your own prices.

Estimated GPU memory to run a language model: weights by precision plus KV cache and overhead.

Reading and speaking time for a word count or pasted text, at research-based reading speeds.

Enter any two of voltage, current, resistance and power to get the other two.

Watts, volt-amps and amps for DC and single-phase AC circuits, with power factor.

kW, kVA and kVAR from line voltage, current and power factor - or the current from kW or kVA.

Volts and percent lost along a copper or aluminium cable, for DC, single-phase and three-phase runs.

Output voltage of a two-resistor divider, or the R2 needed for a target voltage, with an optional load.

Series resistor for one LED or a string: standard E12/E24 value, real current and power rating.

Equivalent of up to 8 resistors or capacitors in series or in parallel.

kVA, kVAR and phase angle from kW and power factor, plus the capacitor kVAR to reach a target.

How long a battery runs a load, from Ah, voltage, depth of discharge and efficiency.

Backup time of a home inverter or UPS battery bank, or the battery Ah needed for the hours you want.

Panels and system kW needed to cover your energy use, from your own peak sun hours.

Daily, monthly and yearly running cost of up to 8 appliances at your tariff.

X% of Y, X as a percent of Y, and the percentage change between two values.

A clean on-screen calculator with keyboard support, correct operator precedence and percent.

Trig in degrees or radians, logs, roots, powers, factorials, pi, e and Ans - typed or tapped.

Add, subtract, multiply and divide fractions and mixed numbers, with the simplified answer.

Mean, median, mode, range, variance, standard deviation and quartiles of any list of numbers.

Credit-weighted GPA for a term, plus the new cumulative GPA when you add prior results.

The score you need on the final exam to reach a target grade, plus best and worst cases.

Real or complex roots of ax^2 + bx + c = 0, with the discriminant, vertex and axis of symmetry.

Attendance percentage, classes to attend to reach 75%, or how many lectures you can still skip.

Course grade from up to 8 weighted parts - homework, quizzes, midterm, final - with an optional letter.

SGPA for each semester and credit-weighted CGPA across all of them, on a 10-point or 4-point scale.

Greatest common divisor (HCF) and least common multiple of 2 to 10 numbers, with Euclid's steps.

Prime test and prime factors with exponents for numbers up to one trillion, plus divisor count and sum.

Simplify a : b (decimals too), scale a ratio to a target amount, or solve a : b = c : x.

Quotient, remainder and repeating decimal, with each divide-multiply-subtract-bring-down step laid out.

Count significant figures digit by digit and round any value to N sig figs, scientific notation included.

Solve a triangle from SSS, SAS, ASA, AAS or two sides of a right triangle: sides, angles, area, type.

Volume and surface area of nine solids, from cube to capsule, in cubic units, litres and gallons.

Exact age in years, months and days, totals in months, weeks and days, and the next birthday.

Years, months and days between two dates or date-times, plus totals in days, weeks and hours.

Count working days between dates or add N business days, with your weekend and holidays.

Sunrise, sunset, solar noon, day length and twilight for any place and date.

Fajr, Sunrise, Dhuhr, Asr, Maghrib and Isha for any place, with the major calculation methods.

ISO 8601 week number, the week's Monday-Sunday dates, day of the year and the US week count.

Hours and minutes between two times, a time plus or minus a duration, or a list of h:mm added up.

Working days between two dates, or N working days on, skipping weekends and official UK bank holidays.

Great-circle bearing to the Kaaba from true north, with a compass rose and the distance to Mecca.

Business days between two dates, or N business days ahead, skipping weekends and observed US federal holidays.

Morning and evening golden hour and blue hour for any place and date, from the sun's elevation.

Fuel needed and trip cost from distance, economy and fuel price, split between passengers.

Monthly car payment with down payment, trade-in, sales tax and fees, plus the total cost.

Cost and energy to charge an electric car between two battery levels, with charging losses.

Diameter, sidewall and revolutions of a tyre size, and the speedometer error of a new size.

Solve speed, distance or time from the other two, in km, miles, metres or nautical miles.

Trip total, per person and per day from stay, food, transport, activities, flights and a buffer.

A car's estimated value year by year, by declining balance or straight line.

Miles times the IRS standard rate for business, medical or charity driving, with a dated trip log.

How long an electric car takes to charge between two levels on a given AC or DC charger.

Yearly fuel versus electricity cost of a petrol car and an EV, the saving and years to repay the price gap.

Total cost of leasing a car against financing and reselling it over the same number of months.

Overall ratio, output rpm and output torque for one to three meshing gear pairs from tooth counts.

Road speed from engine rpm, gear, final drive and tyre size - or the rpm needed for a given speed.

kW per tonne, hp per ton and lb or kg per horsepower for one vehicle, or two compared.

Great-circle distance, initial bearing and midpoint between two latitude and longitude points.

Body mass index with the WHO adult category and the healthy weight range for a height.

Basal metabolic rate from Mifflin-St Jeor or the revised Harris-Benedict equation.

Maintenance calories (TDEE) and daily targets for gradual weight loss or gain.

Body fat percentage from tape measurements with the US Navy method, plus ACE category.

Devine, Robinson, Miller and Hamwi ideal weights side by side, with the healthy BMI range.

An estimated daily fluid range from body weight and exercise time, from published guidance.

Daily grams of protein, carbohydrate and fat from calories and a macro split.

Estimated due date, weeks pregnant, trimester and key dates from LMP, conception or IVF.

Estimated ovulation day and fertile window for the next three cycles.

Estimated max heart rate and five training zones, with optional Karvonen zones.

Pace per km and per mile from distance and time, or finish time from a target pace.

Estimated 1RM from a set of 1-12 reps by Epley and Brzycki, with a training-load table.

Simplify width x height to a ratio and resize to a new width or height without distortion.

Pixel density and dot pitch of any screen from its resolution and diagonal, with labelled presets.

Width, height and area of a screen from its diagonal and aspect ratio, and two screens compared.

Split any length by the golden ratio, find the missing side, and list golden sizes and type steps.

Concrete volume for slabs, footings, round columns or steps, with pre-mix bags and site-mix cement.

Bricks or blocks for a wall from its size and openings, with US, UK, Indian and CMU unit presets.

Tiles and boxes for a floor or wall from its size, the tile size, grout joint and cut waste.

Boxes of laminate, vinyl or wood flooring by box coverage, with a waste allowance for the laying pattern.

Roof area, squares, shingle bundles and underlayment rolls from the footprint, overhang and pitch.

Risers, treads, total run, stringer length and angle for a straight stair, checked against IRC or UK limits.

Decking boards, joists and screws for a rectangular deck from its size, board width, gap and joist spacing.

Fence posts, rails, pickets and post-hole concrete bags for a run of fence with gates.

Cubic yards or metres, tons or tonnes and bags of gravel, crushed stone or sand for an area and depth.

Cubic yards or litres and bags of mulch, topsoil or compost for a bed, with extension depth advice.

Drywall sheets, screws, joint compound and tape for a room's walls and ceiling.

Board feet, cubic metres and cost for up to three lumber line items.

Payback year, lifetime net savings and ROI of a solar system, with tariff rises and panel degradation.

Daily, monthly and annual kWh and specific yield of a solar array from kWp, sun hours and performance ratio.

Battery bank kWh and Ah for days of autonomy, depth of discharge and system voltage, with battery count.

Inverter VA rating from a list of appliances, their surge factors, power factor and headroom.

Generator kW and kVA from running watts and the largest motor's starting surge.

Fuel per hour, runtime per tank and running cost of a diesel, petrol, LPG or gas generator.

Best fixed tilt and facing direction for solar panels at any latitude, with seasonal angles.

Room air conditioner size in BTU/h from floor area, sun, occupants and kitchen use, per ENERGY STAR.

Simplified design heat loss in kW and BTU/h from size, insulation, windows, air leakage and temperatures.

Room airflow in CFM, m³/h or L/s converted to air changes per hour, and back again.

Round duct diameter and an equal-friction rectangular duct from airflow and design velocity.

Dew point from air temperature and relative humidity, or humidity from a dew point, in °C or °F.

The NWS 'feels like' heat index from temperature and humidity, with the official risk category.

Wind chill temperature from air temperature and wind speed, with frostbite risk times.

Dimensional and chargeable weight of a parcel with UPS, FedEx, USPS, DHL Express, IATA or custom divisors.

Carton shipment volume in m³ and ft³, gross weight, and how full a 20' or 40' container would be.

How many identical boxes fit in a 20', 40' or 40' high cube container, by space and payload.

Boxes per layer and per pallet for EUR, ISO, GMA or custom pallets within height and weight limits.

LTL freight density in lb/ft³ and kg/m³, with the 2025 NMFC density-based class for density-rated items.

Trucking fuel surcharge per mile or km from fuel price above a base, or as a percentage of linehaul.

Total and per-unit landed cost of an import: goods, freight, insurance, duty, import VAT/GST and fees.

Inventory turns and days inventory outstanding from COGS, with the stock level needed for a target.

Availability, Performance, Quality and overall equipment effectiveness from shift data.

The production pace customer demand requires, plus the operators a line needs to hold it.

Measured seconds per unit and hourly throughput, checked against a target takt if you have one.

First pass yield per step, rolled throughput yield, scrap rate and optional DPMO for up to six steps.

The stock level that should trigger a purchase order, and how many days remain before you hit it.

Statistical buffer stock from a service level, demand variability and optional lead-time variability.

Economic order quantity, orders per year and the lowest ordering-plus-holding cost, with a cost curve.

MTBF, MTTR, failure rate, inherent availability and mission reliability from a failure log.

Monthly and annual recurring revenue plus ARPA from up to three plans, annual contracts and discounts.

Customer churn and retention for a month, quarter or year, converted between periods by compounding.

NRR and GRR for a customer cohort from starting MRR, expansion, contraction and churned revenue.

Subscription LTV from ARPA, gross margin and monthly churn, with LTV:CAC against the 3:1 benchmark.

Customer acquisition cost from sales and marketing spend, with CAC payback months from ARPA and margin.

Gross and net burn, months of runway and the date cash runs out, with optional revenue growth.

Adds revenue growth and profit margin to test a SaaS company against the 40% bar.

Founder ownership after a priced round, including the option pool shuffle and effective pre-money.

Hourly wage to annual, monthly, biweekly, weekly and daily pay - or a salary back to an hourly rate.

Employer super at 12% per payday and the Payday Super deadline 7 business days later, holidays skipped.

Weekly overtime at 1.5x past 40 hours, or California-style daily overtime and double time - all editable.

Check pay against the UK National Minimum Wage or Living Wage for a worker's age band and apprentice status.

Fully loaded employee cost: salary plus contributions, benefits and overhead, per year and per hour.

Turnover rate from leavers and headcount, annualised from a month or quarter, with retention.

Seven-day timesheet with start, end and unpaid breaks, night shifts, overtime and gross pay.

Last working day from the date notice is given and a notice length in days, weeks or months.

PTO accrued per pay period and the balance projected to a date, with leave taken and a carryover cap.

What a meeting costs in people-time - per minute, per meeting and per year - plus a live running cost meter.

New pay after a raise, the difference per year, month and paycheck, and the real raise after inflation.

A low-to-high range of channel income per day, month and year from views and your own rates.

A price range for a sponsored post or package from expected views, a rate per 1,000 and usage rights.

Monthly sponsorship, paid-subscription and total income for an email newsletter, after platform fees.

Solve file size, duration or total bitrate from the other two, with YouTube's upload bitrate table.

Viewer egress in Mbps or Gbps, data per hour and per event, and the upload speed a streamer needs.

Period food cost percentage from opening stock, purchases, closing stock and food sales, against a target.

Ingredient-by-ingredient batch cost, cost per serving and a suggested price, allowing for trim and waste.

A menu price for one dish from its plate cost, by target food-cost % or markup, rounded to a tidy ending.

Dough weights from flour and baker's percentages, percentages from weights, or flour for N dough balls.

Compare up to three round or rectangular pizzas by area and price per square inch to find the best deal.

Coffee dose or water for pour-over, drip, French press, AeroPress, cold brew or espresso by brew ratio.

Split a wedding budget across venue, catering, photography and more, with cost per guest and editable shares.

Per-head and fixed event costs plus a contingency, giving the total, the cost per guest and a breakdown.

Room capacity for standing, theatre, classroom or banquet layouts, checked against code factors.

Ticket price for a profit target with fees absorbed or passed on, break-even sales and profit at any price.

A dog's age in human years by adult size, plus the 2020 DNA-methylation clock estimate.

A cat's age in human years on the International Cat Care chart, with its life stage.

Daily calories for a dog from RER and life stage, turned into cups or grams of its food.

A cat's daily calories split between dry kibble and wet cans, with a treat allowance.

Estimated whelping date and window from mating, ovulation, LH surge or diestrus dates.

Seed rate in kg/ha or lb/acre from target plants, thousand-seed weight and expected losses.

Plants per bed, per m2 and per hectare for square, triangular or row spacing - or the reverse.

How much N-P-K product meets a nutrient rate, plus the other nutrients and bags it brings.

Weekly irrigation water and run time from reference ET, a FAO-56 crop coefficient and rainfall.

Pre-harvest corn yield from ear counts and kernels, or any crop's production and revenue.

Dry-matter and as-fed feed per head, herd totals for a period and the daily feed cost.

How long a file takes at a given connection speed - or the speed a deadline needs.

Allowed downtime per day, week, month, quarter and year for any availability %, and the reverse.

Usable capacity, efficiency and failures survived for RAID 0, 1, 5, 6, 10, 50 and 60 arrays.