Free Calculators Online

Big decisions deserve better than mental math. NToolHub\'s calculators walk you through loans, investments, health metrics, and grades with clear breakdowns — not just a final number but the steps behind it, so you can sanity-check everything from a mortgage payment to a GPA before it counts.

Age Calculator

Enter your date of birth and get your exact age in years, months and days - plus total days lived and a next-birthday countdown. Free, private, no sign-up.

Average Calculator

Compute the mean of any number list instantly with NToolHub’s free average calculator. Paste values separated by commas, spaces or lines. Fast and private.

Basic Calculator

Do quick addition, subtraction, multiplication and division with NToolHub’s free basic calculator. Full keyboard support and a calculation history included.

BMI Calculator

Calculate your Body Mass Index instantly with NToolHub’s free BMI calculator. Metric and imperial units with a visual category scale. No sign-up needed.

BMR Calculator

Estimate your Basal Metabolic Rate with the Mifflin-St Jeor equation using NToolHub’s free BMR calculator. Includes daily calorie needs by activity level.

Body Fat Calculator

Estimate body fat percentage with the U.S. Navy tape-measure method. Free body fat calculator for men and women, in cm or inches. Instant results.

Break Even Calculator

Find how many units you must sell to cover costs with NToolHub’s free break-even calculator. Get break-even units, revenue and per-unit margin instantly.

Calorie Calculator

Get your personalized daily calorie target with NToolHub’s free calorie calculator. Set goals to lose, maintain or gain weight. Fast, free, private.

Calories Burned Calculator

Estimate calories burned for any workout with NToolHub’s free calories-burned calculator. MET-based estimates by activity, weight and duration.

CGPA Calculator

Compute your CGPA on the 10-point scale with NToolHub’s free CGPA calculator. Add subjects with credits and grade points for an instant result.

Compound Interest Calculator

See how money compounds over time with NToolHub’s free compound interest calculator. Future value, interest earned and a year-by-year table.

Date Difference Calculator

Count days, weeks and months between any two dates with NToolHub’s free date difference calculator. Exact calendar math, instant results.

Discount Calculator

Find sale prices and savings instantly with NToolHub’s free discount calculator. Stack an extra coupon code for the true final price. No sign-up.

Electricity Cost Calculator

Estimate what any appliance costs to run with NToolHub’s free electricity cost calculator. Enter watts, usage and your kWh rate. Instant results.

EMI Calculator

Compute monthly loan installments with NToolHub’s free EMI calculator. Get EMI, total interest and a yearly amortization summary. No sign-up.

Exam Score Calculator

Turn correct answers into a percentage and letter grade with NToolHub’s free exam score calculator. Instant, private, no sign-up needed.

Fraction Calculator

Add, subtract, multiply and divide fractions with NToolHub’s free fraction calculator. Simplified answers plus decimal values, instantly.

Fuel Cost Calculator

Estimate trip fuel cost from distance and efficiency with NToolHub’s free fuel cost calculator. Supports mpg and L/100km. Instant results.

GPA Calculator

Compute your GPA on the 4.0 scale with NToolHub’s free GPA calculator. Add courses with credits and letter grades for an instant result.

Grade Calculator

Find the final-exam score you need with NToolHub’s free grade calculator. Enter current grade and weights for your target score. Instant answer.

Hours Calculator

Compute hours worked between clock-in and clock-out with NToolHub’s free hours calculator. Handles breaks and overnight shifts. No sign-up.

Ideal Weight Calculator

Get your ideal weight range with NToolHub’s free ideal weight calculator. Devine and Robinson formulas, metric or imperial. Instant results.

Investment Calculator

Project SIP investment growth with NToolHub’s free investment calculator. Future value, gains and a year-by-year table. No sign-up.

Loan Calculator

Plan any loan with NToolHub’s free loan calculator. Monthly payment, total interest, total cost and payoff date. Instant, private results.

Markup Calculator

Price products from cost with NToolHub’s free markup calculator. Get selling price, profit per unit and profit margin instantly. No sign-up.

Mean Median Mode Calculator

Get mean, median and mode from any dataset with NToolHub’s free calculator. Plus range, count and sum for full context. Instant, private results.

Mortgage Calculator

Estimate monthly mortgage payments with NToolHub’s free mortgage calculator. Includes down payment, total interest and lifetime cost. No sign-up.

Overtime Calculator

Compute weekly pay with overtime using NToolHub’s free overtime calculator. Time-and-a-half or custom multipliers, full breakdown. Instant.

Pace Calculator

Convert race times to pace and speed with NToolHub’s free pace calculator. Pace per km/mile plus km/h and mph speeds. Instant results.

Percent Decrease Calculator

Find how much a value dropped with NToolHub’s free percent decrease calculator. Decrease amount and percentage, instantly. No sign-up.

Percent Increase Calculator

Measure growth as a percentage with NToolHub’s free percent increase calculator. Get the increase amount and growth rate instantly. No sign-up.

Percentage Calculator

Solve everyday percent problems with NToolHub’s free percentage calculator. X% of Y, X as % of Y, and percent change. Instant answers.

Percentage Change Calculator

Get signed percent change between values with NToolHub’s free calculator. Handles increases and decreases correctly. Instant, private results.

Profit Margin Calculator

Compute profit margin, markup and profit with NToolHub’s free calculator. Enter revenue and cost for instant business insights. No sign-up.

Proportion Calculator

Solve a/b = c/d for the missing value with NToolHub’s free proportion calculator. Fill three values, leave one blank. Instant answer.

Ratio Calculator

Simplify ratios to lowest terms and scale them with NToolHub’s free ratio calculator. Percentage shares included. Instant results, no sign-up.

Retirement Calculator

Project your retirement savings with NToolHub’s free retirement calculator. Monthly compounding, contributions and growth shown. No sign-up.

ROAS Calculator

Measure return on ad spend with NToolHub’s free ROAS calculator. ROAS, ROI, profit and a plain-English verdict on performance. Instant results.

Salary Calculator

Convert annual salary to hourly, weekly and monthly with NToolHub’s free salary calculator. Custom hours per week. Instant breakdown.

Sales Tax Calculator

Add sales tax or extract it from a total with NToolHub’s free sales tax calculator. Any rate, with an instant net/tax/total breakdown.

Savings Calculator

Project savings growth with deposits using NToolHub’s free savings calculator. Balance, interest earned and a yearly table. No sign-up.

Scientific Calculator

Do trig, logs, powers and roots with NToolHub’s free scientific calculator. Full keyboard support, history panel, and offline use included.

Simple Interest Calculator

Compute simple interest with NToolHub’s free calculator. Enter principal, rate and time for interest earned and total amount. Instant results.

Speed Distance Time Calculator

Solve any part of the speed triangle with NToolHub’s free calculator. Find speed, distance or time in km or miles. Instant answers.

Standard Deviation Calculator

Compute population and sample standard deviation with NToolHub’s free calculator. Variance, mean and count included. Instant, private.

Tip Calculator

Calculate tips and split bills with NToolHub’s free tip calculator. Quick tip buttons and per-person shares for groups. Instant, no sign-up.

VAT Calculator

Add or remove VAT at any rate with NToolHub’s free VAT calculator. Clear net, VAT and gross breakdown for any percentage. Fast and private.

Working Days Calculator

Add or subtract working days from any date, skipping weekends and your custom holidays. Free calculator with the result weekday, no sign-up.

About Our Calculators

Each calculator below explains its inputs, validates what you type, and shows detailed results you can trust and share.