---
title: "Grating Resolving Power calculator — AperiOptic"
description: "Spectral resolution R = λ/Δλ from groove density. Free online optics calculator, with the formula and code snippets."
url: "https://aperioptic.com/calculators/grating-resolving-power"
---

# Grating Resolving Power calculator

Spectral resolution R = λ/Δλ from groove density.

Category: [Spectroscopy](https://aperioptic.com/calculators)

Formula: `R = m·N`

## Inputs

| Input | Parameter | Unit | Default |
| --- | --- | --- | --- |
| Lines/mm | `lpm` |  | 1200 |
| Width | `W` | mm | 50 |
| Order m | `m` |  | 1 |
| λ | `lam` | nm | 550 |

## Result with the default inputs

- N grooves: 60000
- Resolving R: 60000
- Δλ: 0.0092 nm

Open it with your own values: put each input in the address as a parameter, for example [`/calculators/grating-resolving-power?lpm=1200`](https://aperioptic.com/calculators/grating-resolving-power?lpm=1200). A unit other than the listed one goes in `<parameter>_unit`.

Read more: [Wikipedia: Diffraction grating, Resolving power](https://en.wikipedia.org/wiki/Diffraction_grating#Resolving_power)

[All optics calculators](https://aperioptic.com/calculators)

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The interactive page: https://aperioptic.com/calculators/grating-resolving-power (AperiOptic runs in the browser; free, no account). Every page of the site as Markdown: https://aperioptic.com/llms.txt