Free calculators that just work

Analyse a rental in one pass — net operating income, cap rate, cash-on-cash return, DSCR and monthly cash flow.

Estimate your monthly mortgage payment, total interest, and payoff cost from the home price, deposit, rate, and term.

Calculate the monthly payment (EMI), total interest, and total cost of any personal or fixed-rate loan.

See how a lump sum plus optional regular deposits grows over time with compound interest.

Work out a percentage of a number, what percent one number is of another, and percentage increase or decrease.

Calculate your Body Mass Index from height and weight, in metric or imperial units, with your category.

Find out how much house you can afford based on your income, debts, and down payment.

See how inflation changes the value of money over time and what a sum will be worth in future.

Work out the sale price and how much you save from a percentage discount.

Find how many calories you need each day to maintain, lose, or gain weight, based on your body and activity.

Calculate your grade point average on the 4.0 scale from your course grades and credit hours.

Estimate your baby's due date from your last period, plus how many weeks pregnant you are and your trimester.

Convert your exam marks into a percentage — enter marks obtained and total marks to get your result and grade.

Compare modeled renter and owner net worth with symmetric cash-flow and investment assumptions.

Solve the nominal annual rate implied by a fixed loan principal, monthly payment, and term.

Model weekly straight-time pay, the regular rate, and an additional overtime premium.

Estimate home-equity borrowing capacity, combined LTV, fixed monthly payment, interest, and fees.

Model interest-only HELOC draws, the balance entering repayment, later amortized payments, and equity capacity.

Compare smallest-balance-first snowball and highest-APR-first avalanche payoff plans with a constant monthly budget.

Estimate a closed-end auto lease payment by separating depreciation, rent charge, payment tax, and signing cash.

Build a year-by-year schedule for a fixed-rate, fully amortizing loan.

Estimate how fixed extra monthly principal changes a mortgage payoff date and remaining interest.

Convert a home down payment between cash and percentage, then estimate the loan amount and LTV.

Estimate APR for a regular fixed-rate loan with equal monthly payments and upfront finance charges.

Compare a current fixed loan payment with a recurring extra payment and estimate time and interest saved.

Estimate your monthly mortgage payment, total interest, and payoff cost from the home price, deposit, rate, and term.

Calculate the monthly payment (EMI), total interest, and total cost of any personal or fixed-rate loan.

Work out your monthly car payment after down payment and trade-in, plus the total interest on your auto loan.

See how long it takes to clear a credit card balance and how much interest you'll pay at a given monthly payment.

Find out how much house you can afford based on your income, debts, and down payment.

See your monthly savings and break-even point when refinancing a mortgage or loan to a lower rate.

Calculate your DTI ratio — the number lenders use to decide how much you can borrow.

Estimate your monthly student loan payment, total interest, and payoff cost.

Find sign-changing internal rates of return for regular signed cash flows, including multiple-IRR warnings.

Estimate a financial-independence target and the time to reach it using a configurable planning withdrawal rate.

Estimate certificate-of-deposit interest and maturity value from disclosed APY and exact term dates.

Discount a signed series of monthly, quarterly, or annual cash flows to period zero.

Project employee contributions, a capped employer match, salary growth, and investment growth in a 401(k).

Project a Roth IRA to retirement age with growing contributions and monthly or year-end timing.

See how a lump sum plus optional regular deposits grows over time with compound interest.

Project how regular monthly investing plus an expected return builds wealth over time.

Find out exactly how much to save each month to reach a target amount by a set date.

Estimate your retirement pot from your current savings and monthly contributions, and the income it could provide.

See how inflation changes the value of money over time and what a sum will be worth in future.

Calculate return on investment as a total percentage and an annualised rate.

Work out the compound annual growth rate between a starting and ending value.

Calculate a stock's dividend yield and the passive income your investment could generate.

Add up what you own and subtract what you owe to see your total net worth and financial health.

Calculate simple interest and the ending balance from a principal, fixed annual rate, and time in years.

Convert a nominal annual interest rate into APY and estimate one year of compounded interest.

Discount one future lump sum to its value today using a fixed annual rate, time, and compounding frequency.

Project what one present lump sum could become at a fixed annual rate and compounding frequency.

Analyse a rental in one pass — net operating income, cap rate, cash-on-cash return, DSCR and monthly cash flow.

Work out capitalization rate from net operating income and price, and value an income stream at a target rate.

Measure annual pre-tax cash flow against the cash you actually invested, including closing and renovation costs.

Calculate debt service coverage ratio — the margin between a property's net operating income and its loan payments.

Estimate how much life insurance coverage your family would need using the DIME method — debts, income, mortgage and education.

Compare your own term and whole life quotes by projecting what the saved premium difference could grow to if invested.

Estimate the monthly disability insurance benefit you would need on top of existing income sources to cover essential expenses.

Convert gross salary and bonus into base-pay and total-compensation hourly equivalents.

Convert a percentage or new base-pay amount across hourly, paycheck, monthly, and annual views while separating bonuses.

Convert an hourly wage into annual, monthly and weekly salary — and back.

Estimate 2026 US take-home pay after federal income tax, Social Security and Medicare, for any pay frequency.

Calculate 2026 self-employment tax — Social Security and Medicare on 92.35% of net profit, plus the Additional Medicare Tax where it applies.

See the difference between your marginal tax bracket and your actual effective tax rate for 2026, with a full bracket-by-bracket breakdown.

Solve real power, voltage, or current for DC, single-phase AC, and balanced three-phase AC scenarios.

Estimate drywall surface, layer coverage, waste, and whole sheets using editable panel dimensions.

Estimate posts, equal intervals, and horizontal rail length for one or more independent straight fence runs.

Calculate board-foot lumber volume from thickness, width, length, equal-piece count, units, and explicit waste.

Estimate flooring area and whole packages from room dimensions, exclusions, waste, and labeled box coverage.

Estimate simple gable roof surface, roofing squares, and whole bundles from plan dimensions, pitch, waste, and coverage.

Estimate whole tiles and boxes from rectangular surfaces, exclusions, waste, actual tile face dimensions, and box count.

Estimate rectangular gravel volume in cubic yards and metres, plus weight from an editable supplier density.

Estimate mulch volume for a rectangular bed and whole bags from the labeled package volume.

Estimate wall paint from equal wall dimensions, openings, coats, product coverage, reserve, and can size.

Calculate the total square footage of one or more equal rectangles with exact metric conversions.

Estimate rectangular slab volume, ready-mix allowance, and whole bags from package-specific yield.

Estimate appliance electricity use and cost from power, runtime, schedule, device count, and price per kWh.

Compare two package prices after converting count, mass, or volume to one consistent unit.

Calculate and convert the area of rectangles, triangles, circles, trapezoids, parallelograms, and ellipses.

Calculate and convert volumes for seven common prisms, round solids, cubes, and pyramids.

Evaluate bounded real-number expressions with powers, roots, logs, factorials, and trigonometry.

Solve a plane triangle from SSS, SAS, or two angles and an opposite side, with unit conversion.

Break an integer into exact prime powers and count its positive divisors.

Solve a missing side of a right triangle and convert the result between length units.

Work out a percentage of a number, what percent one number is of another, and percentage increase or decrease.

Split the bill and work out the tip per person in seconds — choose the tip percent and number of people.

Work out the sale price and how much you save from a percentage discount.

Add sales tax or VAT to a price to see the tax amount and total you'll pay.

Calculate your grade point average on the 4.0 scale from your course grades and credit hours.

Work out profit margin and markup from your cost and selling price — and see the difference between them.

Estimate the fuel cost of any trip from the distance, your vehicle's efficiency, and the price of fuel.

Add, subtract, multiply, or divide two fractions and get the simplified result plus its decimal value.

Convert your exam marks into a percentage — enter marks obtained and total marks to get your result and grade.

Find the arithmetic mean, median, sum, range, minimum, and maximum for a list of numbers.

Solve the missing fourth term in an equivalent proportion written as a:b = c:x.

Round positive or negative numbers to decimal places, whole places, tens, hundreds, or beyond.

Round a number to 1–15 significant figures and see its scientific notation and rounding place.

Generate up to 100 secure random integers in an inclusive range, with optional duplicate prevention.

Convert a finite decimal to an exact fraction in lowest terms without floating-point approximation.

Reduce one integer fraction to lowest terms and see its mixed-number and decimal forms.

Find the greatest common factor and least common multiple of 2–20 integers.

Convert square metric and international-foot units, hectares, acres, and square miles with explicit land-unit definitions.

Convert metric and cubic volume, explicitly labeled US liquid measures, and international acre-feet.

Convert absolute readings across Celsius, Fahrenheit, kelvin, and Rankine while enforcing absolute-zero boundaries.

Convert length across eleven metric, international imperial, land-mile, and nautical-mile units.

Convert mass across SI units, avoirdupois ounces and pounds, stones, and three distinct tonne units.

Count calendar days to or since a target, with weeks, inclusive endpoints, and a calendar duration.

Count Monday–Friday business days or shift a date while excluding your own observed holidays.

Add or subtract a days-hours-minutes-seconds duration from a 24-hour time and track day rollover.

Find your exact age in years, months and days — plus total weeks, days and hours.

Count the exact time between two dates in years, months, days, weeks and hours.

Add up hours worked between a start and end time, minus breaks — with overnight shifts and optional pay.

Estimate adult resting energy expenditure with the Mifflin–St Jeor equation in metric or US customary units.

Compare estimated daily maintenance energy with planned average intake across a chosen number of weeks.

Estimate an exercise-specific one-repetition maximum from a 1–10-rep set with Brzycki and Epley equations.

Estimate an adult exercise heart-rate range with Tanaka age-predicted maximum and the heart-rate-reserve method.

Calculate your Body Mass Index from height and weight, in metric or imperial units, with your category.

Find how many calories you need each day to maintain, lose, or gain weight, based on your body and activity.

Estimate your body fat percentage from simple tape measurements using the US Navy method.

Work out your running pace per kilometre and mile, plus your speed, from a distance and time.

Estimate a healthy target weight for your height and sex using several established formulas.

Estimate your baby's due date from your last period, plus how many weeks pregnant you are and your trimester.