Unit converter
Convert between mm, m and km, between litres and m³, between grams and kg and much more. You can see the factor, so you can learn the staircase.
Your numbers
The conversions are definitions: the SI Brochure (BIPM, 9th ed. 2019) for prefixes, Pa, J and W; 1 bar = 100 kPa (SI Brochure, 8th ed. 2006, Table 8); KiB/MiB/GiB and 1 B = 8 bit per IEC 80000-13:2008.
Answer
250 cm =
2.5m
How to work it out
- 1250 cm / 100 = 2.5 m2 steps UP the staircase (towards a larger unit) of 10: divide by 10 for each step = divide by 100.
The formula
mm → cm → dm → m: · 10 each time
Length: one step on the staircase is a factor of 10.
mm² → cm² → dm² → m²: · 100
Area: each step is 10 · 10 = 100.
mm³ → cm³ → dm³ → m³: · 1.000
Volume: each step is 10 · 10 · 10 = 1,000. 1 dm³ = 1 litre.
km/h = m/s · 3.6
There are 3,600 seconds in an hour and 1,000 metres in a kilometre.
1 kWh = 1,000 W · 3,600 s = 3.6 MJ
Energy = power · time. A kilowatt-hour is one kilowatt for one hour.
1 bar = 100 kPa = 1,000 mbar
Pressure: 1 Pa is 1 newton per square metre.
1 kB = 1,000 B, 1 KiB = 1,024 B
Data: k always means 1,000. The binary thousand (1,024) is called Ki.
In depth: more numbers and “what if”
250 cm in all units
- millimetre2,500 mm
- centimetre250 cm
- decimetre25 dm
- metre2.5 m
- kilometre0.0025 km
- inch98.4251968504 in