To get an idea of what your RMD will be, you can use calculators which will estimate what it will be in the future based on your current age and account’s current value. Bankrate has a nice one that shows the RMD for all ages from 74 to 100:
Depending on your current account value, you may end up actually having your RMD go up each year. If the RMDs look like they will be excessive, start rolling your IRAs into Roths to avoid that problem later on.