Free Online Calculators & Converters
Fast, accurate tools for math, finance, conversions, and everyday life. No sign-up. No downloads.
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Math Calculators
Solve everyday math problems with our free calculators including percentage, age, and BMI tools.
Financial Calculators
Plan your finances with mortgage, loan, investment, tax, and retirement calculators.
Unit Converters
Convert between units of length, weight, temperature, time, and more instantly.
Everyday Tools
Practical calculators for tipping, discounts, fuel costs, and daily life.
Popular Tools
Percentage Calculator
Calculate percentages, percentage change, and percentage of a number instantly. Free onlin…
Age Calculator
Free age calculator finds your exact age in years, months, weeks, days, hours. Calculate t…
BMI Calculator
Calculate your Body Mass Index (BMI) instantly. Free BMI calculator with metric and imperi…
Mortgage Calculator
Free mortgage calculator with taxes, insurance, and PMI. Calculate monthly home loan payme…
Loan Calculator
Calculate loan monthly payments, total interest, and amortization. Free loan calculator fo…
Compound Interest Calculator
Free compound interest calculator. See how your investments grow over time with regular co…
Discount Calculator
Calculate sale price after discount, percent off, and savings. Free discount calculator fo…
Currency Converter
Free currency converter with live exchange rates. Convert USD, EUR, GBP, JPY, and 50+ worl…
Recently Added
Compound Interest Calculator
Free compound interest calculator. See how your investments grow over time with regular co…
NewInvestment Calculator
Calculate investment returns, ROI, and future value. Free investment calculator with initi…
NewElectricity Cost Calculator
Calculate the cost of running appliances and electronics. Free electricity cost calculator…
NewFuel Cost Calculator
Calculate fuel cost for any trip. Free gas cost calculator with distance, fuel efficiency,…
Free Online Tools for Everyday Calculations
Simple Study Tools offers a growing collection of free online calculators and unit converters designed to be fast, accurate, and easy to use. Whether you're calculating a mortgage payment, converting metric to imperial units, or figuring out a tip at a restaurant, our tools give you instant results without any sign-up or installation.
Each calculator includes a clear explanation of the formula being used, frequently asked questions, and links to related tools so you can solve your problem completely. New tools are added regularly, so check back often or search for what you need using the search bar above.
Our financial calculators help you plan major life decisions—from buying a home to saving for retirement. Math and conversion tools make quick work of school assignments, recipes, travel planning, and DIY projects. Every tool works on desktop, tablet, and mobile devices, so you can get answers wherever you are.