Free tools that save you time
Calculators, converters and everyday tools, each with the formula, a worked example and plain-English guidance. Nothing to install and nothing to sign up for.
Find the right tool
- 01CalculatorsPercentage, age, date, time, loan, savings and salary calculators.19 tools
- 02ConvertersConvert length, weight, temperature, area, volume, speed, time, data storage and cooking units.9 tools
- 03ToolsWord and character counters, a password generator, QR codes, case converter, text cleaner and more.13 tools
- 04ProductivityA Pomodoro timer, to-do list, habit tracker and work hours calculator.5 tools
- 05EducationMath calculators, GPA and grade tools, and step-by-step guides on percentages, fractions, averages and unit conversion.18 tools
Most used
- Percentage CalculatorFind X% of a number, what percent one number is of another, or the total behind a percentage.
- Percentage Increase CalculatorFind the percentage increase between two numbers, or raise a number by a percentage.
- Age CalculatorWork out exact age in years, months and days, plus total days lived and the next birthday.
- Date Difference CalculatorCount the days, weeks, months and working days between two dates.
- Hours CalculatorFind the hours and minutes between two clock times, with an optional unpaid break.
- Average CalculatorMean, median, mode, range and standard deviation for any list of numbers.
- Discount CalculatorWork out the sale price, the amount saved and the effective discount when offers stack.
- Tip CalculatorCalculate the tip, the total bill and each person's share when you split it.
- Loan Payment CalculatorEstimate the monthly payment, total interest and yearly balance of a fixed-rate loan.
How these tools are made
- The working is shown
- Every calculator gives the formula, a worked example and the mistakes people make, so you can check the answer rather than trust it.
- Private by default
- Calculations and text run in your browser. Your numbers and documents are not uploaded, and there is no account to create.
- Tested and corrected
- The calculation logic is covered by automated tests, and pages are updated when we find an error or a rule changes.
Practical guides
All guides- Guide · September 19, 2026How to Add, Subtract, Multiply and Divide FractionsThe four fraction operations, each with one clear rule and one worked example, plus how to simplify and convert mixed numbers.
- Guide · September 19, 2026How to Calculate a Discount and the Sale PriceFind the final price, the saving and the real percentage off, including stacked discounts that do not simply add up.
- Guide · September 19, 2026How to Calculate a Loan PaymentThe standard formula for a fixed-rate instalment loan, worked through with real numbers, plus how interest is split from principal.
- Guide · September 19, 2026How to Calculate a PercentageEvery percentage problem is one of three questions. Here are the formulas, worked examples and a way to check your answer.
- Guide · September 19, 2026How to Calculate a Tip and Split the BillThe tip is the bill times the percentage. Here is the formula, an even-split example and mental shortcuts you can do at the table.
- Guide · September 19, 2026How to Calculate Age From a Date of BirthAge is a count of complete years, then leftover months and days. Here is the method and the leap-day edge case.