Money, health, maths, dates and everyday numbers worked out for you. There are 46 of them here, and every one runs inside your browser — no upload, no queue, no account.

Everything in this category

Add or Subtract Days — Find the date a set number of days, weeks or months away.
Age Calculator — Exact age in years, months, days — and every other unit going.
Area Calculator — Area and perimeter for rectangles, circles, triangles and more.
Aspect Ratio Calculator — Scale dimensions while keeping the same proportions.
Average Calculator — Mean, median, mode, range and totals from a pasted list of numbers.
BMI Calculator — Body mass index in metric or imperial, with the standard categories.
Body Fat Calculator — Estimate body fat percentage using the US Navy tape method.
Break-Even Calculator — How many units you need to sell before you start making money.
Calorie and TDEE Calculator — Daily calorie needs from your BMR and activity level.
Car Loan Calculator — Work out car finance payments including trade-in, deposit and sales tax.
Compound Interest Calculator — See how savings grow with regular contributions and compounding.
Credit Card Payoff Calculator — See how long a card balance takes to clear, and what paying more would save.
Date Difference Calculator — Count the days, weeks and months between two dates.
Discount Calculator — Work out a sale price, the saving, and stacked discounts.
Electricity Cost Calculator — What an appliance actually costs to run, per day, month and year.
Fraction Calculator — Add, subtract, multiply and divide fractions, simplified automatically.
Fuel Cost Calculator — Work out what a journey costs in fuel, and split it between passengers.
GCD and LCM Calculator — Greatest common divisor and lowest common multiple of any list of integers.
GPA Calculator — Work out a weighted grade point average from your courses.
Grade Calculator — Turn a score into a percentage and a letter grade.
Inflation Calculator — See what an amount is worth after years of inflation, in both directions.
Leap Year Checker — Check whether a year is a leap year, and find the next few.
Loan Calculator — Monthly payment, total interest and payoff totals for any fixed-rate loan.
Macro Calculator — Split a daily calorie target into protein, carbs and fat.
Margin and Markup Calculator — Convert between cost, price, profit margin and markup.
Mortgage Calculator — Work out monthly repayments, total interest and the true cost of a mortgage.
Paint Calculator — How much paint a room needs, allowing for coats, doors and windows.
Percentage Calculator — Every common percentage question, answered at once.
Percentage Change Calculator — Measure growth or decline between two numbers.
Pregnancy Due Date Calculator — Estimate a due date and see the current stage of pregnancy.
Prime Number Checker — Check whether a number is prime and see its factorisation.
Print Size Calculator — How large you can print an image before it looks soft.
Quadratic Equation Solver — Solve ax² + bx + c = 0 with real or complex roots, shown step by step.
Ratio Calculator — Simplify ratios, scale them up, and solve for a missing value.
Right Triangle Calculator — Pythagoras, angles, area and perimeter from any two sides.
ROI Calculator — Return on investment, plus the annualised rate over your holding period.
Running Pace Calculator — Convert between pace, speed and finish time for any distance.
Salary Converter — Convert between hourly, daily, weekly, monthly and annual pay.
Sales Tax and VAT Calculator — Add tax to a net price, or strip it back out of a gross price.
Simple Interest Calculator — Interest calculated on the original amount only — no compounding.
Standard Deviation Calculator — Population and sample standard deviation, variance and quartiles.
Tile Calculator — Work out how many tiles a floor or wall needs, including the wastage everyone forgets.
Time Duration Calculator — Work out the time between two clock times, across midnight if needed.
Tip Calculator — Work out the tip and split the bill between any number of people.
Water Intake Calculator — A daily hydration target based on weight, activity and climate.
Working Days Calculator — Count working days between two dates, excluding weekends and holidays.