Scientific Notation Converter — Formats, Prefixes, and Sig Figs

Notation Format Reference

How to Use the Scientific Notation Converter

1. Open the scientific notation converter.
2. Enter a number — decimal (299792458), E-notation (2.998e8), or × 10^ format (2.998×10^8).
3. Select your preferred significant figures (2–6).
4. All five formats appear instantly in the table below.
5. Click Copy next to any row to copy that notation.

Key Constants in Scientific Notation

Speed of light: 3 × 10⁸ m/s

Enter 299792458 to get 2.998 × 10⁸ (4 sig figs) or 3.0 × 10⁸ (2 sig figs). The 3 × 10⁸ approximation is used in calculations where exact precision is not needed — for example, estimating the time for light to travel from the Sun to Earth (~8 minutes).

Avogadro's number: 6.022 × 10²³ mol⁻¹

Enter 6.022e23. This is the number of particles (atoms, molecules) in one mole. It appears in every molar mass calculation in chemistry. The exact value is 6.02214076 × 10²³ — the 6.022 approximation is sufficient for most calculations.

Planck's constant: 6.626 × 10⁻³⁴ J·s

Enter 6.626e-34. This is the quantum of action — the smallest possible unit of energy change. Used in E = hf to calculate the energy of a photon from its frequency. Very small numbers like this are where scientific notation is essential.

Scientific vs Engineering Notation

Scientific notation uses any exponent: 1.5 × 10⁷. Engineering notation restricts the exponent to multiples of 3 (3, 6, 9, -3, -6…): 15 × 10⁶ or 15 M. Engineers prefer this because it aligns with SI prefixes — a 15 MHz signal is clearer than a 1.5 × 10⁷ Hz signal.

Significant Figures Guide

Significant figures represent the precision of a measurement. The rules:

• All non-zero digits are significant: 1234 has 4 sig figs.
• Zeros between non-zero digits are significant: 1004 has 4 sig figs.
• Trailing zeros after a decimal point are significant: 12.50 has 4 sig figs.
• Leading zeros are never significant: 0.0034 has 2 sig figs.