When you order a steak at a restaurant and the menu provides the weight of the steak, for example a 225 gram sirloin (or approximately 8 oz.), when you want to enter that meal to track it you need to remember that provided weight is for 250 grams RAW.
An incredibly helpful rule of thumb to remember is that cooked beef will weigh roughly 75% of its own raw weight. This holds true for almost all preparation methods unless you order it extremely rare or extremely well done however these situations are uncommon. Even so, those outlier circumstances will only change that 75% mark by a few percentages at most. 73-77% most likely.
Please also remember to note that it is highly likely your restaurant prepared steak will be cooked in butter unless you specify otherwise. Including this in your meal tracking will be best for higher reported accuracy.
If you want to perfect cooking your own steaks at home (which I highly recommend!) I suggest picking up a Cast Iron Skillet.
The Cast Iron is my favorite way to prepare steaks and it's super simple to consistently replicate time after time, you can find my own personal recipe for Cast Iron Top Sirloin Steaks here.