Color image to black and white converter

RGB to grayscale image conversion online:

How to convert RGB to grayscale

Gray RGB color code has equal red,green and blue values:

 R = G = B

For each image pixel with red, green and blue values of (R,G,B):

R' = G' = B' = (R+G+B) / 3 = 0.333R + 0.333G + 0.333B

This formula can be changed with different weights for each R/G/B value.

R' = G' = B' = 0.2126R + 0.7152G + 0.0722B


R' = G' = B'  = 0.299R + 0.587G + 0.114B


Pixel with RGB values of (30,128,255)

The red level R=30.

The green level G=128.

The blue level B=255.

R' = G' = B' = (R+G+B) / 3 = (30+128+255) / 3 = 138

so the pixel will get RGB values of:


Currently, we have around 935 calculators, conversion tables and usefull online tools and features to make your life easier or simply help you to do your work or duties faster and in more effective way. These below are the most commonly used by many users at all

And we are still developing more. Our goal is to become the one-stop, go-to site for people who need to make quick calculations or who need to find quick answer for basic conversions.

Additionally, we believe the internet should be a source of free information. Therefore, all of our tools and services are completely free, with no registration required. We coded and developed each calculator individually and put each one through strict, comprehensive testing. However, please inform us if you notice even the slightest error – your input is extremely valuable to us. While most calculators on are designed to be universally applicable for worldwide usage, some are for specific countries only.

This website uses cookies to improve your experience, analyze traffic and display ads. Learn more