Calculators
These nine calculators cover the arithmetic most people look up in a hurry: what a loan really costs, how far a salary stretches across pay periods, how many days sit between two dates. Every one of them shows the formula it used and the numbers it substituted, so you can check the result rather than take it on trust. Nothing you type is sent anywhere.
All 9 calculators
Percentage Calculator
Work out a percentage of a number, what percentage one number is of another, or the percentage change between two values. Shows every step.
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Loan Calculator
Calculate a fixed-rate loan payment, total interest and full amortisation schedule. Add an extra monthly payment to see how much sooner it clears.
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Mortgage Calculator
Estimate a monthly mortgage payment including property tax, insurance and HOA fees, with loan-to-value, total interest and a full amortisation table.
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Compound Interest Calculator
Project savings growth with any compounding frequency and regular contributions. Shows the yearly balance, total contributions and interest earned.
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Salary Calculator
Convert pay between hourly, daily, weekly, biweekly, semimonthly, monthly and annual rates using your own hours and paid weeks. Gross pay only.
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Age Calculator
Find an exact age in years, months and days from any birth date, plus total weeks and days lived, the day of the week born and the next birthday.
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Date Difference Calculator
Count the days, weeks, months and years between two dates, with options to include the end date or to count business days only.
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BMI Calculator
Calculate body mass index in metric or US units, see the standard adult category and the healthy weight range for your height. Information only.
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Calorie Calculator
Estimate resting metabolic rate and daily calorie needs with the Mifflin-St Jeor equation, plus illustrative targets for gradual loss or gain.
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Which one should you use?
For borrowing questions, start with the loan calculator. Switch to the mortgage calculator when property tax, insurance and HOA fees need to be part of the monthly figure.
Use the compound interest calculator for money that grows over time, including regular contributions. The loan calculator is for money that is paid down over time.
The salary calculator converts between pay frequencies. It does not estimate tax, so treat every figure it shows as gross pay.
The age and date difference calculators share the same calendar engine. Pick age for birthdays and milestones, date difference for project timelines and business-day counts.
The BMI and calorie calculators are general information tools. They are not a substitute for advice from a qualified health professional.