Metric Conversion
Choose meters, grams or liters, enter a value and pick two prefixes. You get the exact result plus the power of 10 and how many places to move the decimal point. For example, 1.5 km is 1,500 m and 250 mg is 0.25 g.
Last updated November 4, 2026
Result
1.5 km = 1,500 m
| Unit | Power of 10 | Value |
|---|---|---|
| nanometers (nm) | 10^-9 | 1,500,000,000,000 |
| micrometers (µm) | 10^-6 | 1,500,000,000 |
| millimeters (mm) | 10^-3 | 1,500,000 |
| centimeters (cm) | 10^-2 | 150,000 |
| decimeters (dm) | 10^-1 | 15,000 |
| meters (m) | 10^0 | 1,500 |
| decameters (dam) | 10^1 | 150 |
| hectometers (hm) | 10^2 | 15 |
| kilometers (km) | 10^3 | 1.5 |
| megameters (Mm) | 10^6 | 0.0015 |
| gigameters (Gm) | 10^9 | 0.0000015 |
Prefixes are exact powers of ten, so results are exact, with no rounding.
Show the work
Formula: result = value x 10^(from exponent - to exponent)
- Entered: 1.5 kilometers (km).
- Prefix powers: kilo = 10^3, base unit = 1.
- Shift = 3 - (0) = 3, so multiply by 10^3.
- Move the decimal point 3 places to the right (the number gets bigger because the new unit is smaller).
- 1.5 km = 1,500 m (meters).
Result: 1.5 km = 1,500 m
How metric prefixes convert
result = value × 10^(from exponent − to exponent)
Every metric prefix stands for a power of ten. Kilo is 10³ (1,000), hecto is 10², deca is 10¹, deci is 10⁻¹, centi is 10⁻², milli is 10⁻³, micro is 10⁻⁶ and nano is 10⁻⁹. Mega is 10⁶ and giga is 10⁹. The base unit, with no prefix, is 10⁰, which is 1.
To convert, subtract the exponent of the target prefix from the exponent of the starting prefix. That difference is the power of ten to multiply by. Going from kilo (3) to base (0) gives 3, so you multiply by 1,000. Going from milli (−3) to base (0) gives −3, so you multiply by 1/1,000. A positive shift moves the decimal point right, and a negative shift moves it left.
See how we calculate for the formulas, sources and review schedule behind every calculator.
Also useful alongside this calculator: Weight Converter and Volume Converter.
Move the decimal point
Because the factors are powers of ten, a metric conversion never needs a calculator: you only move the decimal point. Converting to a smaller unit makes the number bigger, so the point moves right. Converting to a bigger unit makes the number smaller, so the point moves left. The number of places equals the difference between the two exponents.
For example, 1.5 km to m moves the point 3 places right and gives 1,500 m. And 250 mg to g moves it 3 places left and gives 0.25 g. The converter shows this step for every result.
The prefixes in this converter
The converter covers eleven steps: nano (n), micro (µ), milli (m), centi (c), deci (d), the base unit, deca (da), hecto (h), kilo (k), mega (M) and giga (G). Symbols are case sensitive: a capital M means mega, while a lowercase m means milli, and a capital G is giga.
The results table lists the value in every prefix at once, so you can see the whole ladder for one quantity.
Meters, grams and liters
You can apply the prefixes to three base quantities: the meter (m) for length, the gram (g) for mass and the liter (L) for volume. A kilometer is 1,000 meters, a kilogram is 1,000 grams and a milliliter is one thousandth of a liter.
Strictly, the SI base unit of mass is the kilogram, and prefixes are applied to the gram. This tool follows that convention, so 1 kg equals 1,000 g, and a megagram is 1,000,000 g, which is one metric tonne. The liter is not an SI unit but is accepted for use with the SI, and the capital L avoids confusion with the digit 1.
Exact results without rounding errors
Computers often show tiny errors when they multiply decimals, for example 1.1 × 100 can come out as 110.00000000000001. This converter shifts the digits of your number instead of multiplying, so the answer is exact. The only limit is the size of the number you can enter: values from −1e15 to 1e15.
Writing unit names correctly
Write a symbol without a plural s: 5 km, not 5 kms. Spelled out, a unit is singular only for exactly 1, so you write 1 kilogram and 2 kilograms, and 0.5 liters. The converter follows this rule in its results and table.
How to use the Metric Conversion
- Enter the value and choose meters, grams or liters.
- Pick the prefix you are converting from, and the prefix you want.
- Read the result, the power of 10 and the decimal shift, then use Copy, Print or Share.
Worked example
To convert 1.5 kilometers to meters, kilo is 10³ and the base unit is 10⁰, so the shift is 3 − 0 = 3. Multiply by 10³ by moving the decimal point 3 places right: 1.5 becomes 1,500. So 1.5 km is exactly 1,500 m. The table shows other conversions of the same kind.
| From | To | Shift | Decimal move | Result |
|---|---|---|---|---|
| 1.5 km | m | 10^3 | 3 places right | 1,500 m |
| 250 mg | g | 10^-3 | 3 places left | 0.25 g |
| 2 L | mL | 10^3 | 3 places right | 2,000 mL |
| 35 cm | m | 10^-2 | 2 places left | 0.35 m |
| 4 kg | mg | 10^6 | 6 places right | 4,000,000 mg |
Frequently asked questions
How do I convert kilometers to meters?
Multiply by 1,000, or move the decimal point 3 places to the right. For example, 1.5 km is 1,500 m.
What is the difference between milli and micro?
Milli is one thousandth (10^-3) and micro is one millionth (10^-6), so 1 milligram is 1,000 micrograms.
Why is a capital M mega and a lowercase m milli?
Metric symbols are case sensitive. Capital M is mega, 1,000,000 times the base unit, while lowercase m is milli, one thousandth.
Which way does the decimal point move?
Moving to a smaller unit makes the number bigger, so the point goes right. Moving to a bigger unit makes it smaller, so the point goes left.
Does this converter handle US customary units?
No. It only converts between metric prefixes. For pounds, ounces, gallons or feet, use the weight, volume or length converters.