SI prefix converter
Convert milli to deci
1 m = 0.01 d — to convert milli to deci, divide by 100.
Milli to deci calculator
1 m = 0.01 d
Milli to deci at a glance
1 m = 0.01 d
÷ 100
2 places left
10⁻³ → 10⁻¹
Milli to deci formula and conversion factor
Every SI prefix is a whole power of ten. Milli is 10⁻³ of the base unit and deci is 10⁻¹, so the two are exactly 2 powers of ten apart. That makes the factor exactly 100 — not an approximation, and it never changes with the unit you are measuring.
d = m ÷ 100
10⁻³ ÷ 10⁻¹ = 10⁻² = 0.01
1 m = 0.01 d
5 m = 0.05 d
100 m = 1 d
1000 m = 10 dMilli to deci conversion table
The values people look up most often, converted exactly. Read down for milli (m), across for deci (d).
In words: 10 m is 0.1 d, 100 m is 1 d, 500 m is 5 d, 1000 m is 10 d, 2000 m is 20 d, and 5000 m is 50 d.
| Milli (m) | Deci (d) |
|---|---|
| 0.0009 m | 0.000009 d |
| 0.001 m | 0.00001 d |
| 0.005 m | 0.00005 d |
| 0.008 m | 0.00008 d |
| 0.01 m | 0.0001 d |
| 0.02 m | 0.0002 d |
| 0.05 m | 0.0005 d |
| 0.1 m | 0.001 d |
| 0.2 m | 0.002 d |
| 0.4 m | 0.004 d |
| 0.5 m | 0.005 d |
| 1 m | 0.01 d |
| 2 m | 0.02 d |
| 5 m | 0.05 d |
| 7 m | 0.07 d |
| 10 m | 0.1 d |
| 20 m | 0.2 d |
| 50 m | 0.5 d |
| 100 m | 1 d |
| 200 m | 2 d |
| 250 m | 2.5 d |
| 300 m | 3 d |
| 400 m | 4 d |
| 500 m | 5 d |
| 800 m | 8 d |
| 1,000 m | 10 d |
| 2,000 m | 20 d |
| 5,000 m | 50 d |
How to convert milli to deci without a calculator
Move the decimal point 2 places to the left, padding with zeros if you run out of digits. Going to a larger prefix always makes the number smaller, because each unit now covers more of the quantity.
The check that catches almost every mistake: compare the two exponents before you write the answer. Milli is 10⁻³, deci is 10⁻¹. If the prefix you are moving to is smaller, the digits must grow. If your answer moved the wrong way, you divided when you should have multiplied — the failure mode behind more than one real unit-conversion incident.
Milli to deci FAQ
- How do you convert milli to deci?
- To convert milli to deci, divide by 100. That is the same as moving the decimal point 2 places to the left. For example, 1 m = 0.01 d, and 5 m = 0.05 d.
- How many milli are in 1 deci?
- There are exactly 100 milli in 1 deci. Deci (d) is 10⁻¹ of the base unit and milli (m) is 10⁻³, so they sit 2 powers of ten apart — a factor of exactly 100, with no rounding.
- Is 1 milli equal to 1 deci?
- No. Milli and deci are different SI prefixes 2 powers of ten apart. Milli is 100 times smaller than deci, so 1 m = 0.01 d.
- Is the milli to deci conversion exact?
- Yes. Every SI prefix is a whole power of ten, so milli to deci is exactly ÷ 100 with no rounding. This calculator shifts the decimal exponent instead of multiplying in binary floating point, so a value like 1.001 m returns an exact result rather than one with a trailing rounding error.
- Is milli bigger or smaller than deci?
- Milli is smaller. Milli is 10⁻³ and deci is 10⁻¹, which makes milli 100 times smaller. The number always moves the other way: a quantity written in the smaller unit uses the bigger number.