Everyday Calculators
These are the calculators for life admin and small daily questions. Work out an exact age or how many days until a birthday, total the hours on a weekly time card, add up durations, calculate a GPA or the score you need on a final, and plan the fuel cost of a road trip. Practical converters cover tire sizes, shoe sizes across countries and cooking measurements by ingredient, and two weather tools explain how hot or cold it really feels.
11 free tools · no sign-up · no ads
All Everyday Calculators (11)
Age Calculator
Exact age in years, months and days, next birthday and generationTime Card Calculator
Weekly hours from clock-in and clock-out times, with breaks and overtimeTime Calculator
Add and subtract hours, minutes and secondsGPA Calculator
Semester and cumulative GPA from grades and creditsFinal Grade Calculator
Score you need on the final exam to reach a target gradeFuel Cost Calculator
Trip fuel cost and fuel economy in MPG or L/100 kmTire Size Calculator
Compare tire sizes: diameter, sidewall and speedometer errorShoe Size Converter
Convert shoe sizes between US, UK, EU, Japan and foot lengthCooking Measurement Converter
Convert cups, grams, tablespoons and oven temperatures by ingredientHeat Index Calculator
Feels-like temperature from air temperature and humidity, plus dew pointWind Chill Calculator
Wind chill temperature and frostbite risk from temperature and wind speed
Which tool do I need?
Find out exactly how old someone is
Enter a birth date to see the age in years, months and days, the total days lived and the next birthday.
Add up the hours on my timesheet this week
Enter start and end times and breaks for each day to get daily and weekly totals, with overtime split out.
See what I need on the final to keep my grade
Enter your current grade, the final's weight and your target to get the score you need, then check the GPA it produces.
Estimate the fuel cost of a road trip
Enter the distance, fuel economy and price per gallon or litre to get the trip cost and the cost per passenger.
Convert a recipe from cups to grams
Pick the ingredient so the conversion uses its real weight, and convert oven temperatures too.
About Everyday Calculators
Each calculator updates as you type and explains its rules, such as how months are counted in an age, how a time card rounds minutes or how a GPA weights credits. The weather calculators use the formulas published by the US National Weather Service, and the cooking converter uses ingredient-specific weights because a cup of flour weighs far less than a cup of sugar.
Some answers follow conventions that vary. Shoe size charts differ between brands, GPA scales differ between schools and overtime rules differ between states and countries. Where that is the case, the calculator lets you change the scale or rule and says which standard it uses by default.
Guides
- Age, Time Cards and Time Arithmetic: How the Counting WorksWhy an exact age is counted by anniversaries, what to do with a 29 February birthday, how to turn punches into decimal payroll hours, and why 7.45 hours is not 7:45.
- GPA and Final Grades: The Weighted Averages Behind Your TranscriptHow grade points and credits make a GPA, what weighting really adds, how to plan a cumulative target, and the one formula that tells you what you need on the final.
- Fuel Costs, MPG and Tire Sizes: The Driving Maths ExplainedWhy US and UK MPG disagree, why L/100 km is the fairer unit, what a trip really costs in gas or electricity, and how a tire size code turns into diameter and speedometer error.
- Cups, Grams and Shoe Sizes: Everyday Conversions That Trip People UpWhy a cup of flour is not a cup of sugar, how US, metric and Australian spoons differ, how gas marks map to Fahrenheit, and why shoe sizes never line up between countries.
Frequently asked questions
How does the age calculator count months?
It counts whole calendar months from the birth date and then the remaining days, the way people state ages, and handles leap years and month lengths correctly.
Why does a cup of flour convert to a different weight than a cup of sugar?
Cups measure volume and grams measure weight. Flour is lighter for its volume than sugar, so the cooking converter asks for the ingredient.
Are shoe size conversions exact?
No. They follow common reference charts, and brands size differently. Measure your foot length in centimetres for the most reliable match.
What is the difference between heat index and wind chill?
Heat index shows how hot it feels when humidity slows sweating; wind chill shows how cold it feels when wind strips heat from skin. Each applies only in its own temperature range.