Online calculators
Practical calculators for quick everyday decisions.
Use free tools for finance, health and math. Each calculator combines a functional form, clear result and a short guide explaining the formula.
Available tools
Choose a calculator
The calculators below are built to be fast, responsive and easy to understand, with direct links to the full tool pages.
Compound Interest Calculator
Simulaté final amount, invested total and accumulatéd interest with recurring contributions.
Finance - Investments
BMI Calculator
Calculate body mass index with weight and height and see the adult classification.
Health - Body index
Percentage Calculator
Calculate percentages, discounts, increases and percentage variation between values.
Math - Percent
Rule of Three Calculator
Solve direct and inverse proportion problems with three known values and one unknown.
Math - Proportion
Days Between Dates Calculator
Calculate the number of days, weeks and business days between two dates.
Productivity - Deadlines