Guides
How each calculator works: the formula, where the numbers come from and when to trust the result.
Health
- How the BMI calculator worksBody mass index from your height and weight, with the healthy range for your height.
- How the Calorie calculator worksYour daily maintenance calories (TDEE) and targets for losing or gaining weight.
- How the Body Fat calculator worksEstimate your body fat percentage from tape measurements using the US Navy method.
- How the Ideal Weight calculator worksYour ideal body weight from the Robinson, Miller, Devine and Hamwi formulas, compared side by side.
Education
- How the CGPA calculator worksCumulative grade point average from your semester GPAs and credits, on 4.0 and 10-point scales.
- How the GPA calculator worksGrade point average for a semester from your letter grades and credit hours.
- How the Grade calculator worksYour current weighted grade from assignments, and the score you need on the final to hit a target.
- How the Marks to Percentage calculator worksPercentage from the marks you obtained out of the total, with the matching grade band.
Finance
- How the Loan EMI calculator worksMonthly instalment for a loan, with total interest and a month-by-month amortisation table.
- How the Compound Interest calculator worksHow a lump sum grows with compound interest and optional regular contributions.
- How the Mortgage calculator worksMonthly repayment for a home loan, with total interest, payoff date and a yearly balance breakdown.
- How the Tip calculator worksTip amount, total bill and the per-person split for any group size.
Math
- How the Percentage calculator worksWhat is X% of Y, what percent X is of Y, and the percentage change between two numbers.
- How the Average calculator worksMean, median, mode and range of any list of numbers, with the working shown.
- How the Fraction calculator worksAdd, subtract, multiply or divide two fractions and get the simplified result with the steps.
Date & Time
- How the Age calculator worksYour exact age in years, months and days from any date of birth, plus your next birthday.
- How the Date Difference calculator worksDays, weeks, months and working days between any two dates.
- How the Countdown calculator worksDays, hours and minutes until any date or event, updating live.