SciNotate

Scientific Notation Calculator

Big numbers, small numbers — same format.

Number

Scientific notation

1.234560 × 10^+5

What you entered

Number: 123,456

1
Find the exponent (power of 10)
⌊log₁₀|123456|⌋= 5
2
Divide by 10 to that power to get the mantissa
123456 ÷ 10^5= 1.2346

Result

Scientific notation: 1.234560 × 10^+5

123,456 written in scientific notation is 1.234560 × 10^+5.

Everyday numbers rewritten in scientific notation

Type any number in the left column into the input box and this calculator returns the notation shown, written as a coefficient between 1 and 10 times a power of 10. The coefficient is always given to six decimal places.

Number	Scientific notation	Exponent	Where a number this size shows up
7,900,000,000	7.900000 x 10^+9	+9	People alive on Earth
299,792,458	2.997925 x 10^+8	+8	Speed of light in metres per second
93,000,000	9.300000 x 10^+7	+7	Miles from the Earth to the Sun
1,000,000	1.000000 x 10^+6	+6	One million
123,456	1.234560 x 10^+5	+5	The value the calculator loads with
5,000	5.000000 x 10^+3	+3	A five thousand dollar balance
0.5	5.000000 x 10^-1	-1	One half
0.025	2.500000 x 10^-2	-2	2.5 percent written as a decimal
0.00042	4.200000 x 10^-4	-4	0.42 millimetres expressed in metres
0.000001	1.000000 x 10^-6	-6	One micrometre in metres

The exponent is just how many places the decimal point moves: positive to the left for large numbers, negative to the right for small ones. Notice that 299,792,458 comes back as 2.997925, rounded at the sixth decimal place, so the notation is a display of the number rather than a lossless copy of it. Spreadsheets and programming languages write the same value with an E in place of the power of 10, as in 2.997925E+8.

Compressing huge and tiny numbers

Scientific notation writes a number as a value between 1 and 10 multiplied by a power of 10 — instead of writing 0.0000034, you write 3.4 × 10⁻⁶, which is both shorter and easier to compare in scale to other numbers.

Where it's essential

Astronomy (distances between stars), chemistry (atoms per mole), and computing (bytes of storage) all deal in numbers too large or small to write out comfortably in full — scientific notation is the standard fix.

Frequently asked questions

How do I write 0.00042 in scientific notation?

Move the decimal point right until you have a number between 1 and 10: 4.2. You moved 4 places right, so the exponent is −4. Result: 4.2 × 10⁻⁴.

How is scientific notation different from engineering notation?

Scientific notation always uses an exponent that puts exactly one non-zero digit before the decimal point (e.g., 3.2 × 10⁵). Engineering notation restricts the exponent to multiples of 3 (10³, 10⁶, 10⁹…) so it aligns with SI prefixes like kilo, mega, and giga — more practical for electrical and mechanical engineering.

My calculator shows '3.2E5' — what does that mean?

The 'E' is shorthand for '× 10 raised to the power of.' So 3.2E5 = 3.2 × 10⁵ = 320,000. Most programming languages and spreadsheets use this E-notation because superscript isn't available in plain text.

How do I multiply two numbers in scientific notation?

Multiply the mantissas and add the exponents. Example: (3 × 10⁴) × (2 × 10³) = 6 × 10⁷. If the mantissa product exceeds 10, adjust: (5 × 10⁴) × (3 × 10³) = 15 × 10⁷ = 1.5 × 10⁸.