Calculators
Percentages, BMI, loans, compound interest, tips and dates — instant answers with the working shown.
All 15 calculators
Percentage Calculator
X% of Y, X as a % of Y, and percentage increase or decrease.
BMI Calculator
Body mass index with category and healthy range — metric or imperial.
Age Calculator
Exact age in years, months and days, plus next-birthday countdown.
Loan Calculator
Monthly payment and total interest for any loan or mortgage.
Compound Interest
How savings grow over time, with a year-by-year breakdown.
Tip Calculator
Tip, total and per-person split — live as you type.
Date Difference
Days between two dates, and date ± days for deadlines.
Discount Calculator
Sale price and savings — with stacked discounts and tax.
Calorie Calculator
BMR, maintenance calories (TDEE) and targets to lose or gain weight.
Mortgage Calculator
Monthly payment with taxes, insurance & PMI, plus amortization table.
Salary Converter
Hourly ↔ annual pay with daily, weekly, bi-weekly and monthly figures.
GPA Calculator
Semester and cumulative GPA from grades and credits, weighted or not.
Sleep Calculator
Best bedtimes and wake-up times based on 90-minute sleep cycles.
Time Zone Converter
Convert a date and time to any list of cities — DST-aware, with day changes.
Currency Converter
Convert 30+ currencies with daily ECB reference rates, in your browser.
About these calculators
These calculators give you the answer instantly as you type — and, more importantly, they show the working. The loan calculator breaks every payment into principal and interest, the compound interest calculator charts your balance year by year, and the percentage calculator handles all three ways a percentage question can be asked.
Use the percentage calculator for discounts and tax, the BMI calculator in metric or imperial units, the age calculator for an exact age in years, months and days, the loan calculator to compare monthly payments, the compound interest calculator to project savings with monthly contributions, the tip calculator to split a bill, and the date difference calculator to count days to a deadline. Everything runs in your browser — nothing you type is stored or sent anywhere.
Frequently asked questions
Are the results accurate?
Yes — the formulas are the standard ones (amortization, compound interest with monthly contributions, WHO BMI ranges) and results have been verified against hand calculations. Rounding is applied only at the final displayed digit.
Is the loan or interest output financial advice?
No. The calculators show the mathematical result of the numbers you enter. Real loan offers include fees, insurance and rate changes — always check the lender’s official schedule before deciding.
Is anything I type saved?
No. Calculations happen in the page as you type and nothing is transmitted or stored. Refreshing the page clears everything.
Do these work on a phone?
Yes — every calculator is responsive and works in any modern mobile browser, with no app to install.