First Starter from yeast slurry

This is my fist starter from washed wlp001 only 3 weeks old. I plan to pitch a 1l starter when I brew on sunday. My question is do i need to step up the starter in increments or just start with the full liter. I have a quart mason jar with about 1/2 in of yeast cake.
Thanks in advance

It sounds like you have let the yeast settle out and you have just the clear amber liquid on top. If that's the case, then 1/2" of thick yeast is about 80 mL. You should check out the Mr. Malty site, and input the OG, brew size, and the yeast harvest date. Then click on the "repitching from slurry" tab. Move the yeast concentration "arrow" all the way to the right. That will give you the amount of yeast you need in mL. Since you know you already have about 80 mL, you will then know how much more you need to build up to to have an adequate amount.
I went and inputted 5 gal and a harvest date of 12-7 (3 weeks old) and it tells me you could do a beer with an OG of about 1.054 or under. Anything higher than this and you would be better off making a starter and growing a few more yeast cells.

Thank you much