'Fraid it's not quite as simple as you're probably hoping.
The engine manufacturers provide data for power/RPM/MAP at different mixture settings.
For a fixed pitch prop, the aircraft manufacturer can then convert this to Power/RPM/Altitude/IAS graphs for a particular aircraft in level flight.
In most VP aircraft there is a combination of RPM/MAP/Altitude/fuel flow settings that give a particular power setting.
For typical fixed pitch there are some rules of thumb that work quite well. e.g. 2550/2400/2300 = 75/65/55% on a small lycoming.
Take-off and climb in the average fixed pith a/c is somewhat less than 100% power as you won't reach 100% RPM given the lower IAS in the climb. A 'cruise' propeller will just reach 100% RPM at fulll throttle in level flight at a higher speed.