Free online calculators
Money, health and maths, plus a few just for fun. Everything works as you type and stays in your browser.
Fun
- Cat Age CalculatorEnter your cat’s age to see the human-year equivalent and life stage. A year is not seven years for cats either.
- Dog Age CalculatorEnter your dog’s age and size to see how old they are in human years. We show two methods, since the old 7 × rule is a myth.
- FLAMES CalculatorThe school-days name game, done for you. Enter two names and see what FLAMES says about you.
- Love CalculatorType two names and see your love percentage. It is a classic game, so treat the score as fun, not fate.
- Pizza Size CalculatorIs the large worth it? Enter the diameter and price of two pizzas and see which is the better deal.
- Age on Other Planets CalculatorHow old would you be on Mars, or Mercury, or Jupiter? Enter your birthday and see your age on every planet.
- Zodiac Compatibility CalculatorPick two star signs and see how they match, with the reasoning shown so you can argue with it.
- Zodiac Sign CalculatorEnter a date of birth and see the zodiac sign, element and ruling planet, plus the Chinese animal for that year.
Finance
- Car Lease CalculatorEstimate a monthly lease payment and see how much goes to depreciation, interest and tax.
- Car Loan CalculatorPrice, down payment, trade-in and term in one place. See the monthly payment and what the car really costs.
- Compound Interest CalculatorFind out what a lump sum and regular deposits can grow into, and how much of the result is interest on interest.
- Credit Card Payoff CalculatorEnter your balance, APR and monthly payment. See how long it takes and how much interest it costs.
- Home Affordability CalculatorEnter your income, debts and down payment. See the home price and monthly budget that common lending rules suggest.
- Hourly to Salary CalculatorSee what an hourly wage adds up to over a week, month and year, or what a salary works out to per hour.
- Inflation CalculatorPrices rise, so money buys less over time. See by how much, using any inflation rate you choose.
- Loan CalculatorSee what a loan really costs: the monthly payment, the interest, and how extra payments change the finish line.
- Mortgage CalculatorEstimate your monthly payment, total interest and payoff date. Add taxes, insurance and extra payments to see the real cost.
- Overtime Pay CalculatorEnter your hourly rate, regular hours and overtime hours. See what the extra hours add to your pay.
- Profit Margin CalculatorEnter your cost and price to get margin and markup, or set the margin you want and find the price.
- Refinance CalculatorCompare your current loan with a new rate and term. See the monthly saving and when it pays for the fees.
- Retirement CalculatorEnter your age, savings and monthly contribution. See what you could have by retirement, in today’s money too.
- ROI CalculatorPut in what you paid and what it is worth now. Get the return, the profit, and the yearly rate.
- Sales Tax CalculatorAdd tax to a price, or take it out of a total. Enter your combined state and local rate.
- Savings Goal CalculatorName the amount and the date. We work out the monthly deposit that gets you there.
- Simple Interest CalculatorEnter the principal, the yearly rate and the time. Get the interest and the total, with compound interest alongside.
- VAT CalculatorAdd VAT to a price, or work backwards from a price that already includes it. Rates for the UK and Europe are built in.
Health
- BMI CalculatorEnter your height and weight to see your body mass index and the healthy weight range for your height.
- BMR CalculatorHow many calories does your body burn at rest? Compare the three standard formulas in one place.
- Body Fat CalculatorEnter a few tape measurements. Get an estimate of body fat percentage, with fat and lean mass.
- Calorie CalculatorTell us where you are, where you want to be and by when. We work out the daily calories that get you there.
- Running Pace CalculatorFind your pace, finish time or distance in kilometres or miles, with race times and splits at that pace.
- Sleep CalculatorTell us when you need to wake up, or when you are going to bed, and we will suggest times that fit whole sleep cycles.
- TDEE CalculatorFind how many calories you burn in a day, then see what to eat to lose, maintain or gain weight.
Math
- Basic CalculatorA simple calculator for everyday sums, with a live preview, memory, percent and history.
- Circle CalculatorEnter any one measurement of a circle and get the other three straight away.
- Fractions CalculatorAdd, subtract, multiply and divide fractions and mixed numbers. The answer is reduced to lowest terms.
- Graphing CalculatorType a function of x and see its graph straight away. Plot up to four at once, zoom in and read values.
- Percentage CalculatorPick the question you have and fill in two numbers. The working is shown so you can check it.
- Pythagorean Theorem CalculatorPick the side you want, enter the other two, and get the answer plus area, perimeter and angles.
- Quadratic Equation CalculatorEnter a, b and c for ax² + bx + c = 0. Get the roots, discriminant and vertex at once.
- Scientific CalculatorTrigonometry, logarithms, roots, powers and factorials, with a live preview of the answer as you type.
Everyday
- Age CalculatorEnter a date of birth and see exactly how old someone is, down to the day.
- Color CalculatorMix two colours, convert hex to RGB, HSL and CMYK, find the complement and check text contrast, all in one place.
- Days Between Dates CalculatorPick two dates and see the gap in days, weeks, months and working days.
- Discount CalculatorFind the sale price, the percentage off, or the price before the sale. Add a second discount or tax if you need to.
- Fuel Cost CalculatorEnter the distance, your car’s fuel economy and the fuel price. See the cost, fuel used and each person’s share.
- Tip CalculatorEnter the bill, pick a tip and how many of you are paying. We do the sum.
Converter
- Feet and Inches CalculatorAdd or subtract lengths in feet and inches without converting by hand. Handy for building, sewing and measuring heights.
- Roman Numeral ConverterTurn numbers into Roman numerals, or decode a Roman numeral, and see how it is built letter by letter.
- Temperature CalculatorConvert Celsius, Fahrenheit and Kelvin. Type a temperature and see all three scales at once.
- Unit ConverterPick a type, choose two units and type an amount. You also get the same amount in every other unit of that type.
Home
- Concrete CalculatorEnter the size of your slab, footing or columns. See the volume, how many bags to buy, and when ready-mix makes more sense.
- Paint CalculatorMeasure the room, count the doors and windows, and see how much paint to buy. Metric and imperial.
- Tile CalculatorEnter the room and tile size. See how many tiles to buy, including grout gaps and extra for cuts.
No calculator matches that yet. Try a broader word like “loan” or “age”.