Calculators
Online Calculators
Use quick calculators for common planning and reference tasks, including fraction arithmetic, exact LCM/GCF steps, decimal-to-fraction conversion, CPS testing, and browser-local reaction-time checks. Results are designed for estimation, comparison, learning, and everyday checks rather than regulated advice.
Tools
Popular calculator utilities
Percentage Increase CalculatorUse this free Percentage Increase Calculator to calculate percentage increase between two numbers locally in your browser.
Birthday CalculatorUse this free Birthday Calculator to calculate age and days until a birthday locally in your browser.
Loan CalculatorUse this free loan calculator to estimate monthly payments, total interest, and total repayment for a loan in your browser.
BMI CalculatorUse this free BMI calculator to estimate body mass index from height and weight with metric or US units.
Percentage CalculatorUse this free percentage calculator to calculate percentage of a number, percentage change, ratios, discounts, tips, margins, and reverse percentages in your browser.
Age CalculatorUse this free age calculator to calculate exact age in years, months, days, and total days between two dates.
Fraction CalculatorUse this fraction calculator to add, subtract, multiply, or divide fractions, mixed numbers, and whole numbers. It returns an exact reduced fraction, mixed number, decimal check, and concise steps locally in your browser.
LCM & GCF CalculatorFind the least common multiple or greatest common factor of 2 to 15 positive whole numbers. Choose a mode, enter each number, and see the exact result with steps locally in your browser.
Decimal to FractionConvert decimals to fractions exactly, including repeating decimals and nearest-inch fractions. See reduced and mixed-number results in your browser.
CPS TestRun a CPS test to measure mouse clicks, touchscreen taps, or spacebar presses per second over 1, 5, 10, 30, or 60 seconds.
Reaction Time TestTake a free reaction time test in five rounds using a click, tap, Space, or Enter, then see your median response time in milliseconds.
Date CalculatorUse this free date calculator to count days between dates or add and subtract calendar time in your browser.
Time CalculatorUse this free time calculator to find hours between times, add or subtract time, or total simple work hours in your browser.
Date CalculatorUse this free Date Calculator to calculate days between dates or add and subtract calendar time locally in your browser.
Calculators
Online Calculators guide
Free online calculators for loans, BMI, age, dates, time, percentages, exact fraction and LCM/GCF arithmetic, CPS, reaction time, and everyday checks.
Use quick calculators for common planning and reference tasks, including fraction arithmetic, exact LCM/GCF steps, decimal-to-fraction conversion, CPS testing, and browser-local reaction-time checks. Results are designed for estimation, comparison, learning, and everyday checks rather than regulated advice.
Best for
- Estimate monthly loan payments.
- Calculate BMI with metric or US units.
- Find percentage increases, decreases, discounts, and ratios.
- Add, subtract, multiply, or divide fractions and mixed numbers exactly.
- Convert finite or repeating decimals to reduced fractions and ruler measurements.
- Measure mouse, touch, or spacebar inputs per second with a fixed timer.
- Measure visual response time across five trials without sending exact results.
- Calculate age from a date of birth.
- Count days between dates or add time to a calendar date.
- Calculate hours between times, add minutes, or total work hours.
Limit
Calculator outputs are quick estimates. They do not replace medical, financial, tax, legal, or professional advice.
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