Standard form calculator and unit converter
Type a number to see it in standard form, rounded to the significant figures you choose, and convert between the units used in IGCSE Maths, Chemistry and Physics.
Free · no sign-up · works in your browser
Standard form
4.52 × 10⁻⁴
As an ordinary number: 0.000452
Standard form is A × 10ⁿ with 1 ≤ A < 10. Big numbers have a positive power, numbers smaller than 1 a negative power.
Unit converter
1.5 m
In standard form: 1.50 × 10⁰ (3 s.f.)
Celsius and kelvin
25 °C = 298 K · and 25 K = -248 °C
IGCSE Physics uses T (in K) = θ (in °C) + 273.
Standard form in one minute
- A number in standard form is A × 10ⁿ, where 1 ≤ A < 10 and n is a whole number.
- 45 000 = 4.5 × 10⁴ (the decimal point moved 4 places left).
- 0.0032 = 3.2 × 10⁻³ (moved 3 places right, so the power is negative).
Unit traps
- 1 m² = 10 000 cm², not 100 cm². Area and volume conversions use the square and cube of the length factor.
- 1 dm³ = 1000 cm³ = 1 litre.
- To change km/h to m/s, divide by 3.6.
Questions students ask
How do I type a number already in standard form?
Write it as 4.5 × 10^7, 4.5x10^-3 or 4.5e7.
How many significant figures should I give?
In IGCSE Maths, give non-exact answers to 3 significant figures unless the question says otherwise.