The NumberTrove library
Everyday math
calculators.
Percentages, dates, ratios, and averages — answered in seconds.
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20 everyday math calculators
What Percent Is One Number of Another?
Find what percentage one number is of another with a clear part-and-whole calculation.
Everyday mathPercentage Increase Calculator
Calculate the percentage increase from an original value to a new value.
Everyday mathPercentage Decrease Calculator
Calculate the percentage decrease from an original value to a reduced value.
Everyday mathPercentage Difference Calculator
Compare two values using the percentage difference based on their average.
Everyday mathReverse Percentage Calculator
Find the original amount when you know a percentage and the resulting part.
Everyday mathPercentage Error Calculator
Calculate percentage error by comparing an observed value with an accepted reference value.
Everyday mathShow 11 more everyday math tools ↓
Tip calculator
Calculate a tip and split the total bill between people.
Everyday mathTime duration calculator
Find the elapsed time between a start and end time.
Everyday mathFraction calculator
Add, subtract, multiply, or divide two fractions.
Everyday mathRatio calculator
Scale a ratio to find the missing equivalent amount.
Everyday mathAverage calculator
Find the simple average of up to five numbers.
Everyday mathRandom number generator
Generate a random whole number within a range.
Everyday mathStatistics calculator
Summarize a list of numbers with count, sum, mean, median, minimum, maximum, range, and mode.
Everyday mathQR code generator
Create a scannable QR code from text, a URL, contact details, or any short message without uploading it.
Everyday mathWord and character counter
Count words, characters, sentences, and paragraphs in any text.
Everyday mathBasic calculator
Add, subtract, multiply, or divide two numbers.
Everyday mathAdvanced calculator
Evaluate scientific math expressions with functions, constants, and powers.
Everyday mathHow to choose the right everyday math calculator
Everyday math is usually about getting one dependable answer quickly: a percentage of a price, the change between two numbers, the days between dates, or the average of a list. NumberTrove brings those common tasks together with calculators for percentages, percentage change, age, date differences, time duration, fractions, ratios, averages, random numbers, and general arithmetic. Use these pages when a quick calculation matters more than setting up a spreadsheet.
Pick the percentage calculator for “what is X% of Y,” and percentage change when you are comparing an old value with a new one. Age and date-difference tools use dates rather than arithmetic shortcuts; time duration is useful for shifts and elapsed time. Fractions and ratios help with recipes, scale, and proportions, while averages summarize a list. Check the input order, units, and whether endpoints or overnight hours should be included. When two formulas seem to give different answers, write down the question in words first; the intended direction of the calculation is often the difference.
Check the units and the order of the inputs before calculating. When a result is used for money, health, or a purchase, treat it as a planning aid and verify the assumptions.
Every tool is free, browser-based, and shows its formula, assumptions, and related calculators. Start with the closest match, then adjust the inputs to fit your situation.