Free Online Calculators
Fast, accurate calculators for finance, math, health, dates, and more.
Finance
View all →Amortization Calculator
Free amortization calculator with a full loan payment schedule. Calculate monthly or bi-weekly payments, total interest, and see how extra payments reduce your loan term. Works for mortgages, auto loans, personal loans, and student loans.
Auto Loan & Car Payment Calculator
Calculate your monthly car payment, auto loan interest, and total cost. Free car payment calculator with trade-in value, sales tax, fees, extra payments, amortization schedule, and a "What Can I Afford?" mode.
Compound Interest Calculator
Calculate how your savings and investments grow over time with compound interest. See year-by-year breakdowns, compare compounding frequencies, and factor in regular contributions and inflation.
Tip Calculator
Calculate tip amount, total bill, and per-person split for any meal. Supports custom tip percentages and group splitting.
Mortgage Payment Calculator
Free mortgage payment calculator to estimate your monthly house payment, total interest, and full amortization schedule. Calculate mortgage payments for fixed-rate home loans with optional extra payments and early payoff.
Health & Fitness
View all →Calorie & TDEE Calculator
Free calorie calculator to estimate your daily calorie needs, BMR, and TDEE. Uses the Mifflin-St Jeor and Katch-McArdle formulas to calculate maintenance calories, weight loss targets, and macronutrient breakdowns.
BMI Calculator
Calculate your Body Mass Index (BMI) from height and weight. Includes BMI category classification and a reference table for all ranges.
Pregnancy Due Date Calculator
Free pregnancy calculator to estimate your due date, track gestational age, and view your prenatal schedule. Supports 5 calculation methods including LMP, conception date, ultrasound, IVF transfer, and known due date.
Math
View all →Concrete Calculator
Calculate how much concrete you need in cubic yards, cubic feet, and number of bags. Supports slabs, columns, footings, tubes, and stairs with adjustable waste factor and cost estimator.
Percentage Calculator
Three percentage calculations in one: find a percentage of a number, find what percent one number is of another, and calculate percentage change between two values.
Education
View all →GPA Calculator
Calculate your semester and cumulative GPA on the standard 4.0 scale. Supports weighted GPA for AP, Honors, and IB courses. Plan ahead with the target GPA calculator to find out what grades you need to reach your goal.
Grade Calculator
Calculate your weighted course grade based on assignments, tests, and exams. See your current letter grade and find out exactly what score you need on your final exam to reach your target grade.
Unit Conversion
View all →Time
View all →Age Calculator
Calculate exact age in years, months, and days from a birth date. Also shows total days, total weeks, total months, and next birthday countdown.
Business Days Calculator
Calculate the number of business days between two dates or find a future/past date by adding or subtracting working days. Automatically excludes weekends and U.S. federal holidays with a full breakdown of results.
Date Calculator
Calculate days between two dates or add and subtract days, weeks, months, and years from any date. Shows results in multiple formats with date facts like day of year, week number, and quarter.
Hours Calculator
Free hours calculator to find the hours and minutes between two times, or add up multiple time durations. Calculate hours worked, total shift time, and convert between decimal hours and hours:minutes format. Includes pay calculator.
About CalcuTools
CalcuTools is a collection of free online calculators for finance, math, health, education, and unit conversion. Estimate mortgage payments, calculate percentages, check your BMI, figure out concrete volumes, plan auto loans, and more — with accurate results and clear breakdowns.
Calculators for Every Situation
CalcuTools covers finance, health, math, education, unit conversion, and everyday calculations. Whether you need to estimate a mortgage payment, check your BMI, convert between metric and imperial units, or figure out the right tip at a restaurant, there is a dedicated tool ready to help. New calculators are added regularly based on what people actually search for.
Private, Accurate, and Instant
Every calculation runs entirely in your browser — your numbers never leave your device. All formulas are verified against official sources and industry standards, so the results match what you would get from a scientific calculator or a professional spreadsheet.
Built for Students, Professionals, and Everyone In Between
Students use CalcuTools to check homework and understand how formulas work. Professionals rely on the finance and conversion tools for quick estimates during their workday. Parents use the health calculators for family wellness checks. Whatever brings you here, the goal is the same: get a trustworthy answer fast, then get back to what you were doing.