📐 Metric Length Conversion 2026
Convert between all SI metric length prefixes — from yoctometers to yottameters
1 km = 1,000 m
Move decimal 3 places right
Scientific notation: 1 × 10³ m
📊 All Metric Conversions
SI Metric Prefixes
| Prefix | Symbol | Factor | Decimal |
|---|---|---|---|
| yotta | Y | 10²⁴ | 1,000,000,000,000,000,000,000,000 |
| zetta | Z | 10²¹ | 1,000,000,000,000,000,000,000 |
| exa | E | 10¹⁸ | 1,000,000,000,000,000,000 |
| peta | P | 10¹⁵ | 1,000,000,000,000,000 |
| tera | T | 10¹² | 1,000,000,000,000 |
| giga | G | 10⁹ | 1,000,000,000 |
| mega | M | 10⁶ | 1,000,000 |
| kilo | k | 10³ | 1,000 |
| hecto | h | 10² | 100 |
| deka | da | 10¹ | 10 |
| BASE | m | 10⁰ | 1 |
| deci | d | 10⁻¹ | 0.1 |
| centi | c | 10⁻² | 0.01 |
| milli | m | 10⁻³ | 0.001 |
| micro | µ | 10⁻⁶ | 0.000001 |
| nano | n | 10⁻⁹ | 0.000000001 |
| pico | p | 10⁻¹² | 0.000000000001 |
| femto | f | 10⁻¹⁵ | 0.000000000000001 |
| atto | a | 10⁻¹⁸ | 0.000000000000000001 |
| zepto | z | 10⁻²¹ | 0.000000000000000000001 |
| yocto | y | 10⁻²⁴ | 0.000000000000000000000001 |
Understanding Metric Conversions
📏 The Base Unit
Meter (m) is the SI base unit of length. Originally 1/10,000,000 of Earth's meridian, now defined by the speed of light: distance light travels in 1/299,792,458 second.
🔢 Powers of 10
Each prefix is a power of 10. Moving up one prefix divides by 10 (or 100/1000 for common jumps). Moving down multiplies by 10. Just move the decimal point!
📝 Common Conversions
km to m: ×1000. m to cm: ×100. cm to mm: ×10. m to mm: ×1000. Memorize the powers of 10.
🔬 Scale Reference
Human hair: ~100 µm. Bacteria: ~1 µm. Atom: ~0.1 nm. Earth diameter: 12,742 km. Light year: ~9.46 Pm.
Frequently Asked Questions
How do I convert between metric units?
Move the decimal point based on the difference in powers of 10.
Each step = 1 decimal place. km to m = 3 places right. cm to m = 2 places left.
How many centimeters in a meter?
100 cm = 1 m. "Centi" means hundredth (10⁻²). To convert m to cm,
multiply by 100 (move decimal 2 places right).
How many millimeters in a meter?
1,000 mm = 1 m. "Milli" means thousandth (10⁻³). To convert m to
mm, multiply by 1000.
How many meters in a kilometer?
1,000 m = 1 km. "Kilo" means thousand (10³). To convert km to m,
multiply by 1000.
How do I convert km to cm?
Multiply by 100,000 (10⁵). km → m (×1000) → cm (×100). Example: 2
km = 200,000 cm. Move decimal 5 places right.
What is a micrometer?
1 µm = 10⁻⁶ m = 0.000001 m = 0.001 mm. Also called a "micron."
Human hair is ~70-100 µm thick.
What is a nanometer?
1 nm = 10⁻⁹ m = 0.000000001 m. Used for atoms, molecules,
semiconductors. DNA is ~2 nm wide. Visible light is 400-700 nm.
What is a picometer?
1 pm = 10⁻¹² m. Used for atomic radii. Hydrogen atom radius ≈ 53
pm. 1000 pm = 1 nm.
What is the largest metric prefix?
Yotta (Y) = 10²⁴. 1 Ym = 1,000,000,000,000,000,000,000,000 m ≈ 105
light years. Used for astronomical scales.
What is the smallest metric prefix?
Yocto (y) = 10⁻²⁴. 1 ym = 0.000000000000000000000001 m. Smaller
than any known particle. Theoretical use only.
Why is the metric system decimal-based?
Simplicity! Powers of 10 align with our number system. Converting
just requires moving decimal points. No memorizing 12, 36, 5280 like imperial.
What is scientific notation?
Number × 10ⁿ format. 1 km = 1 × 10³ m. 1 nm = 1 × 10⁻⁹ m. Makes
very large/small numbers manageable. Exponent = decimal places from 1.
What is an angstrom?
1 Å = 10⁻¹⁰ m = 0.1 nm. Not SI, but used in chemistry/physics.
Typical atomic bond lengths are 1-3 Å.
How do I remember metric prefixes?
Mnemonics help: "King Henry Died By Drinking Chocolate Milk" =
kilo, hecto, deka, base, deci, centi, milli. Or just memorize k=10³, c=10⁻², m=10⁻³.
What is a myriameter?
1 myriameter = 10 km = 10,000 m. Historical unit, rarely used
today. "Myria" = 10,000 (10⁴). Not an official SI prefix anymore.
How is the meter defined?
Distance light travels in 1/299,792,458 second (in vacuum). This
definition since 1983 makes the meter incredibly precise, based on a fundamental constant.
How accurate is this metric converter?
Uses exact powers of 10. Conversions are mathematically precise.
Results shown in both standard and scientific notation for accuracy.