Number tools with the working made clear
Check percentages, discounts, fractions, ratios, averages, weighted grades, and simple bill splits.
Start by choosing the comparison you actually need: a part of a whole, a change from a starting value, an exact fraction, or a summary of several observations. These calculators show the assumptions beside the result. They do arithmetic from your inputs rather than supplying missing course policies, prices, or professional advice.
8 tools found
Percentage calculator
Find a percentage, a share, or a percentage change.
Open toolDiscount calculator
See the sale price and exactly how much you save.
Open toolTip & bill split calculator
Add a percentage tip and split the total equally.
Open toolRatio calculator
Simplify a ratio and scale it to a new first value.
Open toolAverage & median calculator
Find the mean, median, range, sum, and count of a number list.
Open toolFraction calculator
Add, subtract, multiply, or divide two fractions exactly.
Open toolWeighted grade calculator
Combine percentage scores using their assessment weights.
Open toolRoman numeral converter
Convert whole numbers from 1–3999 to Roman numerals and back.
Open toolNo tools found
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Name the whole or starting value
Many percentage and ratio mistakes come from the wrong denominator. Write down what each number represents before entering it, and check that units are consistent.
Know which results are rounded
The fraction tool keeps an exact integer fraction. Most other displays round browser floating-point results for readability. Keep enough precision for your task and check any required rounding rule.
Put the tools in context.
All guidesPercentages without the guesswork
A practical way to tell percentages, percentage changes, and percentage points apart.
A ratio, a fraction, and a percentage walk into a plan
Tell part-to-part and part-to-whole comparisons apart before scaling a simple quantity.
Which average answers your question?
Choose between a mean, a median, and a weighted result, with a practical course-score example.