Everyday maths, explained
Each calculator shows the formula it uses alongside the answer, so you can check the working and learn the method. The Percentage Calculator handles the four questions people ask most often, from “what is 15% of 200?” to percentage increase and decrease. For money, the Loan EMI Calculator estimates monthly payments with a year-by-year repayment table, and the Profit Margin Calculator explains the difference between margin and markup.
Dates and times are trickier than they look because months have different lengths and leap years add an extra day. The Age Calculator and Date Difference Calculator use real calendar dates rather than averages, and the Time Duration Calculator handles overnight shifts and breaks. The Unit Converter uses exact international definitions and clearly separates decimal storage units (GB) from binary ones (GiB). The BMI Calculator works in metric or imperial units.
Use results as a guide
Calculations run instantly in your browser and nothing is stored. Results are estimates for planning and learning. A loan calculator is not a lender’s quote, and BMI is a screening measure rather than a diagnosis, so confirm important figures with the right professional.
Calculators FAQ
How accurate are the calculators?
They use standard formulas and double-precision maths. Displayed values are rounded for readability, usually to two decimal places.
Do the date tools handle leap years?
Yes. They count actual calendar days, including 29 February, and explain how they treat month-end dates.
Can I use other currencies?
Yes. The money calculators work with plain numbers, so any currency works the same way.