🔢
Basic Calculator
Standard arithmetic with keyboard support.
🧑‍🔬
Scientific Calculator
Trig, logs, powers and roots, with a DEG/RAD toggle.
💯
Percentage Calculator
X% of Y, X as a % of Y, or the % change between two values.
Fraction Calculator
Add, subtract, multiply and divide fractions, with the working shown.
🔁
Decimal ↔ Fraction
Convert either way, including recurring decimals done exactly.
🔤
Number to Words
Numbers written out in British English, plus ordinal and cheque wording.

Which one do I need?

“What's 15% of 340?” → Percentage Calculator
“Need sin, log or a square root?” → Scientific Calculator
“Add 3/8 and 5/6?” → Fraction Calculator
“Turn 0.625 into a fraction?” → Decimal ↔ Fraction
“Write £1,240 out in words for a cheque?” → Number to Words
“Just need a normal calculator?” → Basic Calculator

Common questions

What's the difference between the basic and scientific calculator?

The basic calculator covers the four operations, percentages and memory keys — everything a desk calculator does. The scientific one adds trig functions, logarithms, powers, roots and a DEG/RAD toggle for anything past arithmetic.

Can these handle recurring decimals?

Yes — the decimal ↔ fraction converter detects recurring digits (like 0.333…) and converts them to an exact fraction rather than rounding, which most converters get wrong.

Is the percentage calculator the same as the one for percentage change?

One tool covers all three: X% of Y, X as a percentage of Y, and the percentage change between two values — so you don't need to remember which formula applies.