Math & Calculators
A set of everyday calculators that compute results instantly in your browser, from percentages and discounts to loan payments, BMI, fractions and unit conversions. Type the numbers and the answer appears - nothing you enter is sent to a server.
These are practical tools for shopping, budgeting, schoolwork and quick engineering checks, with no account and no app to install.
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Age Calculator
Calculate exact age in years, months and days from a birthdate.
Try freeArea & Volume Calculator
Calculate area of 2D shapes and volume of 3D solids.
Try freeBMI Calculator
Calculate your Body Mass Index and find your weight category.
Try freeByte / Bit Converter
Convert between bits, bytes, KB, MB, GB, TB and PB.
Try freeDiscount Calculator
Calculate discount amount, sale price, savings, and discounted value with optional sales tax. Supports stacked coupons.
Try freeFibonacci Sequence Generator
Generate Fibonacci numbers up to any length.
Try freeFraction Calculator
Add, subtract, multiply and divide fractions with simplified results.
Try freeGCD / LCM Calculator
Find the greatest common divisor and least common multiple of two numbers.
Try freeLoan / Mortgage Calculator
Calculate monthly payments, total interest and amortization for any loan.
Try freeNumber Base Converter
Convert numbers between binary, octal, decimal and hexadecimal.
Try freePercentage Calculator
Calculate percentages: X% of Y, percentage increase/decrease, and more.
Try freePrime Number Checker
Check if a number is prime and find all primes up to any limit.
Try freeRandom Number Generator
Generate random numbers within a range with options for uniqueness and sorting.
Try freeRoman Numeral Converter
Convert numbers to Roman numerals and Roman numerals to numbers.
Try freeSalary / Hourly Rate Calculator
Convert between annual salary, monthly, weekly, daily and hourly pay rates.
Try freeScientific Calculator
Full-featured scientific calculator with trigonometry, logarithms and more.
Try freeStatistics Calculator
Calculate mean, median, mode, standard deviation, variance and more.
Try freeTip Calculator
Calculate the tip and split the bill between any number of people. Works as a tip splitter and bill splitter in one.
Try freeUnit Converter
Convert length, weight, temperature, speed, volume and area units.
Try freeCalculators for the numbers you actually use
Most people do not need a scientific package to settle a restaurant bill, check a body-mass index or work out how much a sale price saves. The tools in this category cover the everyday arithmetic that comes up at the shops, at work and in the classroom, and each one computes the result the moment you finish typing. All of the maths happens in your browser with JavaScript, so the figures you enter - salaries, loan amounts, health numbers - are never uploaded or stored by ZeroUtil.
Money, percentages and shopping
For pricing and budgeting, the percentage calculator handles increases, decreases and "X percent of Y", while the discount calculator and tip calculator turn sale tags and bills into the amount you actually pay. For bigger decisions, the loan calculator works out the monthly payment and total interest, and the salary calculator converts between hourly, monthly and annual pay.
Health, study and conversions
The BMI calculator and age calculator answer common personal questions, while the unit converter moves between metric and imperial length, weight, volume and temperature. For schoolwork and engineering, the fraction calculator and area and volume calculator handle the formulas, and the statistics calculator reports mean, median, mode and standard deviation from a list of values.
Number theory and developer maths
- Bases and bytes - the number base converter and byte converter translate between binary, hex, decimal and storage units.
- Factors and sequences - the GCD and LCM calculator, prime number checker and Fibonacci generator cover classroom number theory.
- Conversions and randomness - the Roman numeral converter and random number generator handle the odd jobs.
- Advanced - the scientific calculator covers trigonometry, logarithms and powers when a basic field is not enough.
Why browser-based calculators
Calculators sit in front of personal information surprisingly often - your income, your weight, the size of a loan you are considering. Running them locally means those numbers stay on your device and the result is instant, with no round trip to a server and no waiting. Once the page has loaded the tools keep working offline, which makes them handy on a flaky connection too.
Frequently Asked Questions
What calculators are in this collection?
It groups everyday and study calculators for percentages, discounts, tips, loans, salary, BMI, age, fractions, area and volume, statistics, unit conversion, number bases, byte sizes, GCD and LCM, primes, Fibonacci, Roman numerals, random numbers and a full scientific calculator. They cover most quick maths tasks without needing a spreadsheet.
Are the calculations done privately in my browser?
Yes. Every calculator runs its maths with JavaScript on your own device, so the numbers you type - including income, loan amounts and health figures - are not sent to ZeroUtil or stored anywhere. You can verify this by checking your browser network panel while you use a tool.
How accurate are the results?
The tools use standard formulas and double-precision arithmetic, so results are accurate for normal everyday and educational use. For very large numbers or many decimal places, expect the usual floating-point rounding that all browser-based calculators share, and treat financial figures as estimates rather than official quotes.
Can I use the loan and salary calculators for real decisions?
They are great for comparing scenarios and getting a quick estimate of monthly payments, total interest or take-home pay. For a binding figure, confirm the exact rate, tax bracket and fees with your lender or payroll provider, since those vary by region and contract.
Do I need an account or internet connection?
No account is required and there is nothing to install. Because the maths happens locally, the calculators continue to work even if your connection drops after the page has loaded.