175 tools · free · no signup
Small tools that get the number right.
Calculators and converters for work, pay and everyday problems — built to be correct about the details most of them get wrong.
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- Time Card CalculatorAdd up a week of shifts with unpaid breaks, split regular from overtime hours, and get gross pay.
- Business Days CalculatorCount working days between two dates, or add business days to a date and skip weekends.
- Mortgage CalculatorMonthly payment, total interest and a full amortization schedule, with US or Canadian compounding.
- Scientific CalculatorTrigonometry in degrees or radians, logarithms, powers, roots and factorials.
- Age CalculatorYour exact age in years, months and days, plus how long until the next birthday.
- GPA CalculatorGrade point average on the scale your institution actually uses — 4.0, weighted, 5.0 or a percentage system — rather than one assumed for you.
- Grade Needed on FinalWhat you must score on the final to reach a target grade, and whether that target is still arithmetically reachable at all.
- Character & Word CounterCount characters, words, sentences, paragraphs and lines, with a reading time estimate.
- JSON Formatter & ValidatorFormat, minify and validate JSON, with syntax errors reported by line and column.
- Password GeneratorChoose the length and character sets, then read the entropy in bits and a Weak-to-Very-strong verdict. Built on the Web Crypto API, never Math.random.
- Unit ConverterConvert length, weight, volume, area, speed, data and temperature between any units.
- Fuel Cost CalculatorCost of a trip from distance, fuel economy and price, in US, imperial or metric units.
- Cooking Measurement ConverterConvert cups, spoons, millilitres and grams, accounting for each ingredient.
- Text Diff CheckerCompare two versions of a text and see exactly what changed, line by line or word by word, without uploading either one.
- Cron Expression ParserRead a cron expression back in plain English and list the next times it will actually fire, including the fields people misremember.
- Password Strength AnalyserHow long a password would really survive an offline attack, with the dictionary words, keyboard runs and dates that shorten it named individually.
- Passphrase GeneratorWord-based passphrases with the entropy stated in bits, so you can see why four random words beat a mangled dictionary word you cannot recall.
- Running Pace CalculatorPace, time or distance from the other two, in minutes per kilometre and per mile, with the splits you would need to hold it.
- One-Rep Max CalculatorEstimate a single-rep maximum from a set you actually completed, using several published formulas at once because they disagree more than lifters expect.
- BMI CalculatorBody mass index from metric or imperial measurements, with the WHO category and the healthy weight range for your height.
- BMR & Daily Calorie CalculatorResting metabolism by Mifflin-St Jeor or Harris-Benedict, then daily calories for your activity level and weight goal.
- Fuel Economy CalculatorMiles per gallon or litres per 100 km from a tank and a trip, with the US and imperial gallon kept apart because they are not the same size.
- EV vs Petrol Running CostPence or cents per mile for each, over a year of your own driving, on the electricity and fuel prices you actually pay.
- Electricity Bill CalculatorEstimate a bill from your own tariff, including the standing or monthly fixed charge, or build the usage up from appliance wattages.
Browse by category
All 175 toolsWork & Money
Shifts, pay and the arithmetic behind an invoice.
12 tools
Time Card CalculatorText
Reshape and measure whatever you paste in.
7 tools
Text Diff CheckerStudy & School
Grades, deadlines and revision time. The arithmetic between a syllabus and a week that actually fits, including the one question every student eventually asks: what do I need on the final.
40 tools
Grade Needed on FinalDeveloper
Everyday utilities for building things.
27 tools
Cron Expression ParserSecurity & Privacy
Analysers and generators for the defensive side: checking a policy you wrote, reading a token you were handed, judging how strong a secret really is. Everything runs in your browser and nothing is sent anywhere.
20 tools
Password Strength AnalyserGeneral
The calculators you reach for without thinking.
2 tools
Scientific CalculatorHealth & Fitness
Body, energy and dates, from published formulas.
8 tools
BMI CalculatorFitness & Training
For people training for something. Pace, load, splits and recovery — the arithmetic that sits between a session plan and what actually happened, worked out rather than guessed.
20 tools
Running Pace CalculatorHome & Life
Rooms, bills, groceries and the animals in them.
5 tools
Electricity Bill CalculatorCars & Driving
Running costs, fuel, tyres and what a car is really worth. Arithmetic on the numbers you can measure yourself, and no advice on anything a manufacturer publishes a figure for.
20 tools
EV vs Petrol Running CostDate & Time
Ages, spans, deadlines and countdowns.
7 tools
Business Days CalculatorConversions
Turn one unit into another, correctly.
7 tools
Cooking Measurement Converter
Runs in your browser
Every calculation happens on your device. Nothing you type is sent to us.
No account, no cost
Nothing to sign up for and nothing to install. Open a tool and use it.
Shows its working
Assumptions and units are stated, so you can check the number rather than trust it.