Micrometers Ra to Rq, RMS roughness
Type a value in µm Ra to get it in µm Rq instantly.
1.776µm Rq
That's about the same as a machined surface. A human hair is about 43.75 times that height.
What it means
How rough is that?
Ra is an average of the deviations, so two surfaces with the same Ra can feel and wear quite differently. Ra and Rq relate exactly only for a sine profile.
The math
How to convert µm Ra to µm Rq
To convert micrometers Ra to Rq, RMS roughness, multiply by 1.11.
Example: 1.6 µm Ra × 1.11 = 1.776 µm Rq.
In the other direction, 1 µm Rq = 0.900901 µm Ra.
Every unit
Your roughness in every unit
Tables
µm Ra to µm Rq conversion table
| µm Ra | µm Rq |
|---|---|
| 0.025 µm Ra | 0.02775 µm Rq |
| 0.05 µm Ra | 0.0555 µm Rq |
| 0.1 µm Ra | 0.111 µm Rq |
| 0.2 µm Ra | 0.222 µm Rq |
| 0.4 µm Ra | 0.444 µm Rq |
| 0.8 µm Ra | 0.888 µm Rq |
| 1.6 µm Ra | 1.776 µm Rq |
| 3.2 µm Ra | 3.552 µm Rq |
| 6.3 µm Ra | 6.993 µm Rq |
| 12.5 µm Ra | 13.875 µm Rq |
| 25 µm Ra | 27.75 µm Rq |
| 50 µm Ra | 55.5 µm Rq |
µm Rq to µm Ra conversion table
| µm Rq | µm Ra |
|---|---|
| 0.025 µm Rq | 0.0225225 µm Ra |
| 0.05 µm Rq | 0.045045 µm Ra |
| 0.1 µm Rq | 0.0900901 µm Ra |
| 0.2 µm Rq | 0.18018 µm Ra |
| 0.4 µm Rq | 0.36036 µm Ra |
| 0.8 µm Rq | 0.720721 µm Ra |
| 1.6 µm Rq | 1.44144 µm Ra |
| 3.2 µm Rq | 2.88288 µm Ra |
| 6.3 µm Rq | 5.67568 µm Ra |
| 12.5 µm Rq | 11.2613 µm Ra |
| 25 µm Rq | 22.5225 µm Ra |
| 50 µm Rq | 45.045 µm Ra |
Quick answers
Quick answers
- How many µm Rq is 1 µm Ra?
- 1 µm Ra is 1.11 µm Rq.
- How many µm Rq is 10 µm Ra?
- 10 µm Ra is 11.1 µm Rq.
- How many µm Rq is 1.6 µm Ra?
- 1.6 µm Ra is 1.776 µm Rq.
The units
About these units
Micrometers Ra (µm Ra)
The international standard for average roughness.
Rq, RMS roughness (µm Rq)
The root-mean-square version, about 1.11 times Ra on a ground surface.
Keep going