Free Online Calculators
Fast, accurate calculators for the numbers that come up in everyday life – how old you are to the day, what a loan really costs, how many calories you need, what your GPA works out to. Every one runs instantly in your browser and shows the working, not just the answer.
Choose a tool
Age Calculator
Free age calculator: enter your date of birth and get your exact age in years, months and days, plus total weeks, days, hours and your next birthday countdown.
BMI Calculator
Free BMI calculator for adults.
Calorie Calculator
Free calorie calculator: find your BMR and daily calorie needs (TDEE) from age, sex, height, weight and activity level, plus targets for losing or gaining weight.
Percentage Calculator
Free percentage calculator: work out X% of Y, what percent one number is of another, percentage increase or decrease, and add or subtract a percentage.
Loan Calculator
Free loan calculator: enter amount, rate and term to see your monthly payment, total interest and a full year-by-year amortisation schedule.
GPA Calculator
Free GPA calculator on the 4.
Unit Converter
Free online unit converter for length, weight, volume, area, speed, temperature, time and digital storage.
Mortgage Calculator
Free mortgage calculator with down payment, property tax and home insurance.
Date Duration Calculator
Free date calculator: find the number of days, weeks, months and working days between two dates.
Discount Calculator
Free discount calculator: enter the original price and percentage off to see the sale price and how much you save, with optional sales tax or VAT.
Tip Calculator
Free tip calculator: work out the tip and total on any bill, split it between any number of people, and pick a percentage with one tap.
Answers you can check, not just trust
A calculator that spits out a single number is not much use if you cannot see how it got there. Ours show the formula, the intermediate values and – where it matters – a full breakdown table. The loan calculator gives you a year-by-year amortisation schedule; the percentage calculator prints the arithmetic; the age calculator shows totals in months, weeks, days, hours and minutes. You can verify the result or copy the working into a report.
Private and instant
Nothing you type is sent anywhere. The calculations happen in JavaScript on your own device, so results appear as you type and your salary, loan amount, weight or date of birth never touches a server. There is no account, no limit and no waiting.
Frequently asked questions
Are these calculators free to use?
Yes, every calculator is completely free with no account, no usage limit and no watermark on anything you copy or download.
Do you store the numbers I enter?
No. All calculations run in your browser. Nothing you type is transmitted to us, which matters when you are entering financial or health information.
How accurate are the results?
The mathematics is exact – we use standard published formulas such as the amortisation formula for loans and Mifflin-St Jeor for calories. Real-world outcomes vary because lenders add fees and bodies differ, so treat financial and health results as well-informed estimates.
Can I use them on my phone?
Yes. Every calculator is designed mobile-first and works in any modern browser on iPhone, Android, tablet or desktop.
Do the calculators work offline?
Once a page has loaded, yes. You can switch off your connection and keep calculating.