It depends, a ratio of what?

If you're talking molar ratio, then yes. 1 mol of ammonia turns into 1 mol of nitrite turns into 1 mol of nitrate...

If you're talking unit mass, such as mg, then no. 17 mg of ammonia turns into 46 mg of nitrite turns into 62 mg of nitrate.

There's another commonly used unit for that reason, and the answer is yes in that case (I won't mention it at the risk of sounding more confusing).