Free calculators and converters
Find the right calculator fast.
Search by task, browse by topic, or start from the most-used calculators. Results stay quick, private, and easy to revisit.
Popular tasks
Browse
Calculator categories
Most used
Popular calculators
Age Calculator
Calculate age in years, months, and days from a date of birth
Date & Time>BMI Calculator
Calculate adult BMI from height and weight, then use age and sex for an estimated body-fat percentage and contextual guidance
Health>Percentage Calculator
Calculate percent of a number, percent change, discounts, grades, and reverse percentages with clear base-value formulas
Math>EMI Calculator
Calculate EMI, monthly loan payments, total interest, and total repayment from principal, interest rate, and loan term
Finance>Scientific Calculator
Evaluate scientific expressions with trigonometry, logarithms, roots, powers, factorials, constants, parentheses, and degree or radian modes
Math>Calorie Calculator
Estimate daily maintenance calories from age, sex, height, weight, and activity level
Health>US Mortgage Calculator
Estimate a US-style monthly mortgage payment with principal and interest, down payment, property tax, homeowner insurance, PMI or mortgage insurance, HOA dues, total P&I payments, payoff date, amortization tables, charts, and optional extra principal payment
Finance>Compound Interest Calculator
Calculate future value and compound interest from principal, annual rate, term, and daily, monthly, quarterly, or yearly compounding
Finance>TDEE Calculator
Free online TDEE calculator for BMR, maintenance calories, calorie deficit, and weight-loss planning. Use metric or imperial inputs with Mifflin-St Jeor
Health>Fraction Calculator
Add, subtract, multiply, or divide proper, improper, and negative fractions with simplified results and visible working steps
Math>Days From Today Calculator
Find the date a selected number of days from today
Date & Time>Currency Converter
Convert between major world currencies with live exchange rates, fallback snapshots, and a selectable 1-year historical exchange-rate chart
FinanceLearn by changing the inputs
Quick answers with the working shown
Calxo calculators are designed for checking a real decision, not just producing a number. Each tool keeps the inputs visible, explains the formula or assumptions, and lets you test another scenario without creating an account. Use these examples to explore probability and physics, then browse the category pages when you need a more specialized calculator.
For publishers and educators
Embed a calculator or cite the underlying data
Use a responsive calculator inside an article, or download structured catalogue, formula, and source-reference data with clear reuse terms.