A calorie adjustment means deliberately raising or lowering your daily calories when your trend weight has been clearly off your target rate for a few weeks. It is the part of bulking and cutting that most calculators leave out.
Every starting value from a calculator is an estimate. For you as an individual it can be off by a few hundred calories. Only comparing it with your trend shows whether it fits.
When to adjust
Wait two to three weeks before you judge. The scale often swings by one to two kilograms from salt, glycogen and gut content, many times your weekly rate. The first week of a new phase is also distorted by glycogen and water. Do not adjust after a cheat day, when starting creatine, after a program change or in weeks with patchy data.
The calculation
Correction (kcal per day) = (target rate minus measured rate in kg per week) × 7,700 ÷ 7
The 7,700 kcal per kilogram is an approximation, not a fixed constant according to Hall 2008. For small steps it is good enough, because you check the result against your trend anyway. In practice, every tenth of a kilogram per week of difference equals about 110 kcal a day.
Example: Cutting at 85 kg with a target of 0.60 kg per week, you measure 0.30 kg after three weeks. The correction is 0.30 × 1,100 = 330 kcal a day less. This is a worked example.
Then wait again
After every adjustment you need another two to three weeks for the trend to absorb the new days. Small gaps under about a tenth of a kilogram per week are rarely worth correcting, and big jumps make you overshoot in the other direction.