Category
Calculators
Everyday calculators — BMI, percentage, age, tip, date diff.
35 free calculators tools — no sign-up, runs in your browser.
BMI Calculator
Compute Body Mass Index from height and weight in either metric or imperial units.
Percentage Calculator
Compute percent of a number, the percentage one number is of another, and percentage change.
Age Calculator
Compute your age in years, months, and days from a date of birth — plus total days lived.
Date Difference Calculator
Compute the difference between two dates in years, months, days, hours, minutes, seconds.
Tip Calculator
Calculate tip and split a restaurant bill across any number of people.
Timezone Converter
Convert a time from any timezone to any other — Central to Pacific, UTC to Tokyo, you name it.
Aspect Ratio Calculator
Compute aspect ratios and resize dimensions while preserving the original proportion — 16:9, 4:3, 21:9 and more.
Bytes Converter
Convert between bytes, KB, MB, GB, TB and their binary counterparts KiB, MiB, GiB, TiB.
Length Converter
Convert between metric and imperial length units — mm, cm, m, km, inches, feet, yards, miles.
Weight Converter
Convert between metric and imperial weight units — mg, g, kg, tonnes, ounces, pounds, stone, US tons.
Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin and Rankine using the exact formulas, not approximations.
Speed Converter
Convert between m/s, km/h, mph, knots and ft/s — covers driving, flying, sailing and physics units.
Volume Converter
Convert between mL, L, cubic meters, US fluid ounces, cups, pints, quarts, and gallons (US + Imperial).
Coin Flip
Flip a virtual coin once or hundreds of times — cryptographically random, fair 50/50 odds.
Dice Roller
Roll d4, d6, d8, d10, d12, d20 or d100 dice — D&D notation like 3d6+2 supported via the modifier field.
Random Picker
Pick random items from a list — names, options, prizes. Cryptographically fair, with or without duplicates.
Stopwatch (Duration Calculator)
Format, add, or subtract durations like '1:23:45' or '1h 30m'. Heads up — this is a calculator, not a live stopwatch.
Countdown Timer (Time Until)
Calculate how much time until a date — days, hours, minutes, seconds. Heads up: it's a calculator, not a live ticking countdown.
Pomodoro Timer (Schedule Calculator)
Plan a pomodoro study session — how many cycles, work + break minutes, total time. It's a planner, not a ticking timer.
Scientific Calculator
Evaluate math expressions with trig, logs, roots and constants — degrees or radians, all in your browser.
Compound Interest Calculator
Project savings/investment growth with compound interest — set principal, annual rate, years, compounding frequency and optional monthly contribution.
Loan & Mortgage Calculator
Compute monthly payment, total interest, and the amortization schedule for any fixed-rate loan or mortgage.
Discount Calculator
Compute the sale price after a percent discount — supports stacked discounts and an optional sales-tax / VAT addition.
Salary Converter
Convert between hourly, daily, weekly, biweekly, monthly and annual salary — adjust hours/week and weeks/year.
VAT / Sales Tax Calculator
Add VAT/sales tax to a net amount, or extract VAT from a gross amount — also derives the tax portion as a standalone figure.
Time Zone Meeting Planner
Find overlapping working hours across two time zones to schedule meetings — free, runs in your browser.
Electricity Cost Calculator
Calculate your electricity cost from watts, usage hours and rate per kWh — see daily, monthly and yearly estimates instantly.
Fuel Cost Calculator
Calculate the fuel cost for any trip — enter distance, fuel efficiency and price per gallon or liter to see total cost and fuel needed.
GPA Calculator
Calculate your GPA from letter grades and credit hours — supports A+ through F on the standard 4.0 scale.
Number to Words Converter
Convert any number to English words — supports up to trillions, decimals, negatives, and ordinals.
Roman Numeral Converter
Convert between Roman numerals and integers — validates input and handles values from 1 to 3,999.
Scientific Notation Converter
Convert between standard numbers and scientific notation — see mantissa, exponent, and both forms instantly.
IMEI Validator
Validate a 15-digit IMEI with the Luhn check digit and extract the TAC, serial number, and reporting body prefix.
IMEI Generator
Generate valid-format test IMEI numbers with correct Luhn check digits for QA, forms, and modem calculator testing.
Huawei Unlock Code Calculator
Calculate Huawei modem NCK unlock codes for v1, v2, and v201 algorithms, plus the flash code, from a valid IMEI.
Frequently asked
Are Toolsly calculators free?
Yes. BMI, percentage, age, tip, date-difference and all other calculators are free and unlimited.
Are calculations done locally?
Yes. Calculators run in your browser. No input is sent to any server.
Can I use the calculators offline?
Yes. Once the page is loaded, calculators work without an internet connection.