Free online calculators for money, health, math and everyday life
CalcYouNeed shows the answer and the working behind it: the formula, a worked example and the answers to common questions.
Popular calculators
- Mortgage CalculatorEstimate your monthly mortgage payment and total interest.
- Loan CalculatorEstimate your monthly loan payment, total interest and total cost.
- BMI CalculatorCalculate body mass index from height and weight.
- Percentage CalculatorFind a percent of a number, what percent one number is of another, or a percent change.
- Compound Interest CalculatorSee how savings grow with compound interest and monthly contributions.
- Age CalculatorCalculate exact age in years, months and days, and days to the next birthday.
Financial calculators
- Mortgage CalculatorEstimate your monthly mortgage payment and total interest.
- Loan CalculatorEstimate your monthly loan payment, total interest and total cost.
- Compound Interest CalculatorSee how savings grow with compound interest and monthly contributions.
- Discount CalculatorFind the sale price and how much you save, with optional sales tax.
- Savings Goal CalculatorFind how much to save each month to reach a savings goal.
- Credit Card Payoff CalculatorSee how long it takes to pay off a card and how much interest you pay.
- Salary CalculatorConvert hourly pay to annual salary and back, with daily, weekly and monthly pay.
- Sales Tax CalculatorAdd sales tax to a price or remove it from a total.
- Auto Loan CalculatorEstimate your monthly car payment with tax, down payment, trade-in and term.
Health & Fitness calculators
Math calculators
- Percentage CalculatorFind a percent of a number, what percent one number is of another, or a percent change.
- Average CalculatorMean, median, minimum, maximum and sum of a list of numbers.
- Fraction CalculatorAdd, subtract, multiply and divide fractions with simplified results.
- Ratio CalculatorSimplify a ratio and scale it up or down.
- Random Number GeneratorGenerate random whole numbers in any range, with or without repeats.
- Standard Deviation CalculatorStandard deviation and variance for a list of numbers, sample and population.
Everyday calculators
- Age CalculatorCalculate exact age in years, months and days, and days to the next birthday.
- Date Difference CalculatorCount the days, weeks, months and years between two dates.
- Tip CalculatorWork out the tip, the total bill and each share when splitting.
- Unit ConverterConvert length, weight, volume and temperature units.
About these calculators
CalcYouNeed brings together 22 free calculators for the everyday questions people search for: what a loan will really cost, how savings grow, what a percentage change means, or how old someone is on a given date. Every calculator shows the formula it uses and a worked example, so you can check the answer yourself instead of trusting a black box.
The calculators run in your browser and the numbers you enter are not sent to our server. Results are estimates meant to help you understand a situation. For decisions about money or health, talk to a qualified professional. You can also read about how the site works or contact us with a suggestion.
Frequently asked questions
Are these calculators free?
Yes. Every calculator is free to use, with no sign-up and no limits.
Are the numbers I enter saved?
No. Calculations run in your browser, so the numbers you type are not sent to our server.
How accurate are the results?
The formulas are standard ones and each page includes a worked example you can check by hand. Real life can differ because of fees, taxes, changing rates and individual factors, so treat results as estimates.
Can I use the results for financial or medical decisions?
The results are estimates for general information, not financial, tax or medical advice. For important decisions, talk to a qualified professional.
How can I suggest a new calculator?
Send us a message from the contact page and tell us what you would like to calculate.