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Scientific Notation Converter

Tame unwieldy numbers. Convert a plain decimal into scientific notation (and back), and multiply or divide values that are already in scientific form. Essential for chemistry, physics, and anywhere magnitudes span orders of magnitude — from the mass of a proton to the distance to the Sun.

Decimal → Scientific

e.g. 0.000045 or 320000000
0.000045 = 4.5000 × 10⁻⁵

Scientific → Decimal

e.g. 3.2e8, 4.5e-5, 6.02e23
3.2e8 = 320,000,000

How Scientific Notation Works

A number becomes m × 10ⁿ where 1 ≤ m < 10 and n is an integer:

0.000045 = 4.5 × 10⁻⁵   |   320,000,000 = 3.2 × 10⁸

Moving the decimal right to shrink the number gives a negative exponent; moving it left to grow the number gives a positive one. Multiplying/dividing in this form is just mantissa math plus exponent addition/subtraction: (2×10³)(3×10⁴) = 6×10⁷.

Worked Example: The Size of a Virus vs a Star

A typical virus is about 0.000045 m across → 4.5 × 10⁻⁵ m. The Sun is roughly 1.39 × 10⁹ m in diameter. The ratio is about (1.39×10⁹) ÷ (4.5×10⁻⁵) ≈ 3.1 × 10¹³ — thirty trillion times larger. Scientific notation turns that comparison from an unreadable string of zeros into a single clean exponent.

Frequently Asked Questions

What is scientific notation?

A mantissa (1–10) times a power of ten. 0.000045 → 4.5×10⁻⁵.

How do I convert a decimal to it?

Shift the decimal to one non-zero digit left; places moved = exponent (negative for small numbers).

How do I multiply in scientific notation?

Multiply mantissas, add exponents: (a×10ᵐ)(b×10ⁿ) = ab×10ᵐ⁺ⁿ.

How do I divide in scientific notation?

Divide mantissas, subtract exponents: (a×10ᵐ)÷(b×10ⁿ) = (a/b)×10ᵐ⁻ⁿ.

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Reviewed by BuildFormulas Editorial Review Board, Editorial Review
Last updated: August 2026