All calculators
Every free calculator on Apexa Pro — 151 tools across 14 categories, all on one page.
Kids & Learning06
Kids Calculator
A big, colourful, friendly calculator for children to practise the four basic operations.
Base Ten Blocks
Visual addition and subtraction with base ten blocks — see regrouping and borrowing step by step.
Number Line
Visual addition and subtraction within 20 — a friendly frog hops each step.
Fraction Pizza
Build, compare and find equivalent fractions by tapping slices of a pizza.
Telling Time
Learn to read an analog clock: drag the hands to explore, then take a leveled quiz.
Greater Than, Less Than
Compare numbers with the hungry-crocodile game — pick greater than, equal to or less than.
Math23
Percentage Calculator
Percentages, discounts, increases and reverse percentages, solved instantly.
Fraction Calculator
Add, subtract, multiply and divide fractions with fully simplified results.
Random Number Generator
Random numbers by range or list, with or without repeats.
3D Dice Roller
Roll d4 to d100 as real 3D polyhedra that tumble and settle, with three visual styles.
Password Generator
Strong random passwords in your browser, adjustable length and types.
Grade Calculator
Average, weighted average, or the score you need on the final.
Unit Converter
Convert length, weight, temperature and volume, metric and imperial — with a live chart.
Statistics Calculator
Mean, median, mode, range and standard deviation of a list.
Slope Calculator
Slope, line equation, angle and distance between two points.
Density Calculator
Solve density, mass or volume from the density formula.
Speed, Distance & Time Calculator
Find speed, distance or time from the other two, with km/h and mph.
Circle Area Calculator
Area, circumference and diameter from any one measurement.
Length Converter
Convert length between meters, kilometers, miles, feet, inches and more.
Weight Converter
Convert weight between kilograms, grams, pounds, ounces and more.
Temperature Converter
Convert temperature between Celsius, Fahrenheit and Kelvin.
Volume Converter
Convert volume between liters, gallons, cups, tablespoons and more.
Speed Converter
Convert speed between km/h, mph, m/s, knots and more.
Time Converter
Convert time between seconds, minutes, hours, days and years.
Data Storage Converter
Convert data between KB, MB, GB, TB and binary units.
Energy Converter
Convert energy between joules, calories, kWh, BTU and more.
Strong Password Generator
Cryptographically strong passwords with a live entropy meter and rank levels.
Time Zone Converter
The equivalent local time between two cities, with daylight saving handled for you.
Screen Size Comparison
Compare two screens by real surface area, not just diagonal inches, with a scaled visual.
Dates & Time03
Finance27
Auto Loan Calculator
Monthly payment, total interest and the full amortization table.
Airbnb ROI Analyzer
Cash flow, cap rate and profitability scenarios for short-term rentals.
AI Token Cost Calculator
Estimate API budgets for GPT, Claude and Gemini from token usage.
Compound Interest Calculator
Project investment growth with compounding frequency and recurring contributions.
Mortgage Calculator
Monthly payment, total interest and amortization chart for a home loan.
CAGR Calculator
Compound annual growth rate between a starting and ending value.
IRR Calculator
Internal rate of return from an initial investment and a series of cash flows.
Loan Interest Rate Calculator
Find the interest rate from a loan amount, payment and term.
Tip Calculator
Tip amount and total, with per-person bill splitting.
Savings Goal Calculator
How much to save each month to reach a target by a set date.
Break-Even Calculator
Units you must sell to cover costs, from fixed costs, variable cost and price.
Sales Tax & VAT Calculator
Add or remove sales tax, VAT, GST or IVA with an editable rate.
Future Value Calculator
What a single lump sum grows to over time at a given rate.
Net Worth Calculator
Your net worth from total assets minus total liabilities.
Margin Calculator
Sale price from a target margin, or margin and markup from cost and price.
Rental Yield Calculator
Gross and net rental yield from price, rent and annual costs.
Refinance Calculator
Compare your current loan with a refinance: new payment, savings, break-even.
Retirement Calculator
Project your retirement pot from savings, monthly contributions and return.
Discount Calculator
Final sale price and savings, with optional stacked discounts.
Price Change Calculator
Percentage change between prices, or apply an increase or discount.
Live Salary Counter
Watch your pay tick up in real time — how much you earn per second.
Compound Interest Simulator
An animated chart of your savings growing year by year, split into contributions and interest.
Debt Payoff Planner
Plan and animate paying off your debts with the snowball or avalanche method.
Savings Goal Date
The exact month and year you'll reach your savings goal, animated to the finish line.
Split the Bill by Dish
Split a restaurant bill by what each person ate — tax, tip and shared plates, with a clear total per person.
Subscription Cost Tracker
Add your subscriptions and see the real monthly and yearly total, with a bar for each.
Opportunity Cost of Military Spending
Translate a public spending figure into schools, hospitals, teachers, homes or scholarships.
Health10
BMI & Calorie Calculator (TDEE)
Body mass index plus daily calories by activity level.
VO₂ Max Calculator
Estimate your VO₂ max from a 12-minute run or your resting heart rate.
Daily Water Intake Calculator
Recommended daily water from your weight and activity level.
Pregnancy Due Date Calculator
Estimated due date and how many weeks pregnant, from your last period.
Target Heart Rate Calculator
Max heart rate and fat-burn and cardio training zones by age.
Calorie Deficit Calculator
Turn a daily calorie deficit into an estimated weekly weight loss.
Macro Calculator
Split daily calories into grams of protein, carbs and fat.
Ovulation Calculator
Estimate your fertile window and ovulation day from your last period.
Conception Date Calculator
Estimate the likely conception date from an estimated due date.
Sleep Cycle Calculator
The best times to wake up or go to bed, aligned to 90-minute sleep cycles.
Construction & DIY06
Concrete Calculator
Concrete volume and bags for slabs, columns, footings and DIY jobs.
Square Meters Calculator
Area from length and width, plus conversions between m², ft², and more.
Water Tank Capacity Calculator
Volume in litres and gallons for rectangular and cylindrical tanks.
Paint Calculator
Litres of paint needed from wall area, coats and coverage.
Wallpaper Calculator
Rolls of wallpaper needed from wall size, roll size and pattern repeat.
BTU Calculator
Air-conditioner size (BTU) a room needs from area and conditions.
Work & Productivity06
Work Hours Calculator
Hours worked and overtime pay from your start, end and break.
Salary Converter
Convert a wage between hourly, daily, weekly, monthly and annual.
Take-Home Pay Calculator
Net pay from gross salary with an editable deduction rate.
Severance Pay Calculator
Estimate severance from salary, years of service and an editable factor.
Work Tenure Calculator
Your exact time employed in years, months and days, plus accrued vacation.
Freelance Hourly Rate Calculator
The hourly rate to charge based on your target income and the hours you can really bill.
Kitchen & Recipes16
Recipe Cost Calculator
Total cost and cost per serving from your ingredient list, with a cost breakdown chart.
Recipe Calories & Macros Calculator
Total calories, protein, carbs and fat per serving from your ingredient list, with a macro split chart.
Recipe Scaler
Scale any recipe's ingredient quantities up or down by servings or a custom factor.
Kitchen Measurement Converter
Convert cups, tablespoons, grams, milliliters and more — by ingredient, so weight and volume match.
Oven Temperature Converter
Convert oven temperatures between °C, °F and Gas Mark.
Coffee-to-Water Ratio Calculator
How many grams of coffee to use for your water, by method and ratio.
Roast Cooking Time Calculator
Roasting time from the weight and type of meat, with editable minutes per kg.
Coffee Composition
Espresso, milk and foam poured layer by layer, in the real proportions of every coffee drink.
Scoville Scale
The heat of chili peppers in Scoville units, shown as a flame that grows with the spice.
Meat Doneness Guide
Cooking time and doneness for beef, pork and chicken, with an animated cross-section of the cut.
Interactive Pasta Recipe
Classic pasta recipes step by step, with servings that scale and a built-in cooking timer.
Cocktail Recipes
Six classic cocktails poured layer by layer, with exact amounts and the story behind each one.
Aperol Spritz Recipe Calculator
The classic 3-2-1 Aperol Spritz scaled to any number of glasses, poured layer by layer.
Hugo Spritz Recipe Calculator
Prosecco, elderflower and soda in the exact 3-2-1 ratio, scaled to any number of glasses.
Espresso Martini Recipe Calculator
Vodka, coffee liqueur and espresso in exact measures, shaken with ice and scaled to any number of glasses.
Classic Margarita Recipe Calculator
The 2-1-1 classic margarita from scratch — on the rocks or frozen — scaled to any number of glasses.
Auto & Transport05
Fuel Economy Calculator
Fuel economy in L/100km, km/L and MPG from distance and fuel used.
Trip Fuel Cost Calculator
Fuel cost of a trip from distance, consumption and fuel price.
Car Affordability Calculator
Maximum car price from your monthly budget, rate, term and down payment.
Car Depreciation Calculator
What a car will be worth after a few years, with a value chart.
Lease vs Buy Calculator
Which is cheaper — buying or leasing a car over the same term.
Sports & Fitness05
Pace Calculator
Convert between running pace, time and distance.
Race Time Predictor
Predict your race time at any distance from a recent result (Riegel).
One-Rep Max Calculator
Estimate your 1RM from a set of reps, with training percentages.
Calories Burned Calculator
Calories burned by activity from your weight and duration (METs).
World Cup 2026 Players Countdown
From 1,248 players to a single champion: see how many are left at each round.
Events & Celebrations04
Countdown Calculator
A live countdown to any date and time — days, hours, minutes, seconds.
Wedding Budget Calculator
Estimate a wedding total from guests, catering, venue and extras.
Party Drinks Calculator
How many drinks to buy for a party, split into beer, wine and spirits.
Event Food Calculator
How much food to serve at an event from guest count and type.
Countdowns09
4th of July Countdown
Live countdown to US Independence Day, with an animated flag. Rolls over to next year automatically.
Argentina Independence Day Countdown
Live countdown to the 9 de Julio, Argentina's Independence Day.
Brazil Independence Day Countdown
Live countdown to the 7 de Setembro, Brazil's Independence Day.
Christmas Countdown
Live countdown to December 25 with falling snow and a lit tree.
New Year Countdown
Live countdown to January 1. Rolls over to the next year automatically.
Thanksgiving Countdown
Live countdown to the fourth Thursday of November, recalculated each year.
Mexico Independence Day Countdown
Live countdown to the 16 de Septiembre, Mexico's Independence Day.
Colombia Independence Day Countdown
Live countdown to the 20 de Julio, Colombia's Independence Day.
Chile Fiestas Patrias Countdown
Live countdown to the 18 de Septiembre, Chile's national day.
Fun & Curiosities20
Numerology Calculator
Life Path, Destiny and Soul numbers from your birth date and name.
Zodiac Compatibility Calculator
Zodiac signs of two dates and an element-based compatibility score.
Day of the Week Calculator
What day of the week any date fell on, plus how many days ago.
Big Number Calculator
Turn huge amounts of time into a real date from today.
Relationship Calculator
How long you've been together, down to the day, with your next anniversary.
Binge-Watch Calculator
How long to finish a series, in hours and days.
Chinese Zodiac Calculator
Your Chinese zodiac animal and element by birth year.
Name Compatibility Calculator
The classic FLAMES name game — just for fun.
Interplanetary Travel
Pick a planet and a speed and watch a ship make the trip — the time reveals on arrival.
Hail Mary Interstellar Travel
How long to reach the stars of Project Hail Mary — Tau Ceti and Erid — at different speeds, with an animated ship.
Reading Time Calculator
How long a text takes to read, silently or aloud.
Dice Probability Calculator
Exact odds of rolling any sum with any dice.
Lottery Odds Calculator
Your real odds of hitting a lottery jackpot.
Space Travel Time Calculator
How long to reach the Moon, Mars or the stars at any speed.
Celebrity Net Worth Calculator
The fortune of famous people, compared to yours.
Chinese Gender Predictor
Boy or girl, the traditional Chinese way — just for fun.
Your Age on Other Planets
How old you'd be on Mercury, Mars or Neptune, with an animated solar system.
Daily Number Puzzle
Reach 24 using four numbers and + − × ÷ — a fresh brain teaser every day.
Screen Time in Perspective
See what your daily screen time adds up to over years — in movies, books and more.
Baby Name Generator by Numerology
Baby name ideas whose numerology number, with your surname, matches a quality you pick.
Pets & Animals11
Dog Food Calculator
Estimate how much to feed your dog from its weight, life stage and food.
Cat Food Calculator
Estimate how much to feed your cat from its weight, life stage and food.
Dog Years Calculator
Convert your dog's age to human years by size, with the science-based estimate too.
Cat Age Calculator
Convert your cat's age to human years with the standard feline chart.
Litter Box Calculator
How many litter boxes you need with the one-per-cat-plus-one rule.
Dog Pregnancy Calculator
Your dog's likely whelping date from the mating date.
Cat Pregnancy Calculator
Your cat's likely kittening date from the mating date.
Horse Age Calculator
Convert your horse's age to human years.
Rabbit Age Calculator
Convert your rabbit's age to human years.
Aquarium Size Calculator
Tank volume and fish capacity from its dimensions.
Chickens for Eggs Calculator
How many hens you need for the eggs you want.