Put in both offers and a realistic attainment. See year one with the ramp, and a normal year after it.
An offer letter shows OTE, which is what you make at exactly 100% of quota. This compares the two offers at the attainment you think is realistic, which is usually closer to what you'll make.
A normal year is base plus variable at that attainment. Year one also counts the ramp: during the ramp months you earn your guarantee if there is one, and otherwise about half your normal attainment, since new reps rarely sell at full speed. That half is an assumption, and it's shown so you can argue with it.
If one offer has a much bigger quota for the same pay, put in a lower attainment for that job and run it again. Quota Check tells you whether each quota is in the normal range for how it's measured.
This covers cash only, at a straight-line rate. It doesn't include accelerators (Pay Check does), or stock, RSUs and ESPPs, which QuotaBird doesn't value. It isn't financial advice.
I spent six years leading federal partner sales teams at AWS, after plenty of years carrying a number myself. QuotaBird is mostly stuff I wish we'd had back then. Most of it's free. If the problem's messier than a little tool can handle, we can talk it through.