Physics
SI units & dimensional checks
Convert units and check dimensions.
Your measurements
Number formats & units
Use decimal dots in datasets. Single values also accept decimal commas and scientific notation such as 1.2e-3 or 1.2 × 10⁻³.
Calculated locally. No account or uploads.
Result & working
ExampleThe calculator is loading. You can read the worked example below.
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Interpretation & assumptions
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Formula & example
The relationship
What the variables mean
| Symbol | Meaning |
|---|---|
| Base units | kg, m, s, A, K; also dimensionless 1 and rad. |
| Length / time | km, cm, mm, um (μm), nm; ms, min, h. |
| Other supported symbols | g, mA, N, J, eV, W, V, mV, ohm (Ω), kohm, C, Hz, kHz, MHz, Pa, kPa, T, F, L, mL, deg. |
Worked example
- Value
- 2.5
- From unit expression
- cm^2
- To unit expression
- m^2
0.00025 m^2
Follow the example steps
- Both expressions have dimensions m^2.
- Convert to SI: 2.5 × 0.0001 = 0.00025.
- Convert from SI: 0.00025 / 1 = 0.00025 m^2.
Common mistakes
Apply the conversion factor to every dimension.
Incorrect approach
1 cm² = 0.01 m²
Correct approach
1 cm² = (0.01 m)² = 0.0001 m²
More checks before you submit
- Square or cube the conversion factor for area or volume.
- A dimensionless ratio can still have a meaningful physical interpretation.
- Use K, not Celsius, where an absolute thermodynamic temperature is needed.
Method notes
Check an equation by comparing dimensions of its two sides. Matching dimensions are necessary but do not prove that a coefficient or a physical model is correct. Formal dimensional-analysis problem solving is not the objective of this helper.
Operations are read left to right; use explicit powers and products. Write kg*m*s^-2 or kg*m/s^2. Parentheses, addition, equation parsing and Celsius offsets are not supported. Symbols are case-sensitive: m is metre and M is not a standalone unit.
To find gradient units, divide vertical-axis units by horizontal-axis units. To find area units, multiply them. Convert before fitting when axes use different scale factors.