How can set my DPI to 800 in Steelseries Rival 95 PC Bang Edition?

[BobbyDeol]

In the steelseries software the dpi presets are 250, 500, 1000, 1250, 1500, 2000, 4000 and I can only switch my DPI b/w them. I've been playing CSGO with 800 DPI from a very long time and i'm kinda used to it. I know there are some ways in which i can get the same sensitivity by choosing other dpi and then multiplying or dividing it by some number to get what i want but i'm not good with maths? Please tell me if you know how to?
Thank you.

[Muppet among Puppets]

For the math:
1000 is 25% more than 800. Divide sensitivity number ingame by 4 and remove the result from the value you were used to.

For the setting:
Look for the setup program that comes with your product or is on the original homepage.