General Math calculators

Everyday math, with every step shown.

The tools you reach for constantly: percentages, fractions, ratios, and number theory. Each shows the full working, not just the answer.

What lives here

Percentages, percent of, what percent, percent change.
Fractions, add, subtract, multiply, divide with simplification.
Ratios & proportions, simplify ratios; solve a/b = c/d.
Number theory, GCF, LCM, and prime factorization.

Common questions

What is the difference between GCF and LCM?

GCF is the largest number dividing both (used to simplify fractions); LCM is the smallest number both divide into (used to add fractions). They are linked: GCF(a,b) × LCM(a,b) = a × b.

When do I use a proportion vs a percentage?

Use proportions for “a is to b as c is to what” relationships between two ratios. Use percentages when comparing a part to a whole of 100.

Percentage CalculatorPercent of, what percent, percent change.Fraction CalculatorAdd, subtract, multiply, divide fractions.Proportion CalculatorSolve a/b = c/d for the missing value.Ratio CalculatorSimplify ratios to lowest terms.GCF CalculatorGreatest common factor with Euclidean steps.LCM CalculatorLeast common multiple via the GCF.Factor CalculatorPrime factorization with division steps.

Everyday math, step by step

General math covers the calculations that support almost every other topic: fractions, percentages, ratios, proportions, and basic number theory. Students use them in homework and tests, while adults meet the same skills in discounts, recipes, budgets, and measurements. If a problem feels routine but error prone, it probably belongs here.

Choose a calculator below, enter your numbers, and follow the working shown for each step. Seeing the method, not just the final answer, helps you check homework, catch slips, and reuse the same approach on the next problem without help.

Tools in this category

Percentage Calculator – Calculate percent of, what percent, and percent change.
Fraction Calculator – Add, subtract, multiply, and divide fractions with simplification.
Proportion Calculator – Solve a proportion for one missing value.
Ratio Calculator – Simplify a ratio to its lowest terms.
GCF Calculator – Find the greatest common factor of two numbers.
LCM Calculator – Find the least common multiple of two numbers.
Factor Calculator – Break a number into its prime factors.

Frequently asked questions

How do I find a percentage of a number?

Change the percent to a decimal and multiply. For example, 25 percent of 80 is 0.25 times 80, which is 20.

Can a fraction and a decimal give the same value?

Yes. A fraction and a decimal can name the same amount. For example, 3/4 equals 0.75, because 3 divided by 4 is 0.75.

Why simplify a ratio or fraction?

Simplifying keeps the same value in its smallest whole numbers, which makes comparisons and further calculations easier. For example, 6/8 simplifies to 3/4.