Climb rate vs. speed or weight

[Mak]

How can I correct (approximately) rate-of-climb numbers for different speeds or weights?

I did such a test on an C182 I'm planning to buy a share in a few days ago but unfortunately both pilots got the test slightly wrong: we used the speed for MTOW with significantly less than that. Since I'm looking only for an approximate number some form of adjustment for either weight or speed will do.

Thanks.

Mak

[High Wing Drifter]

You could accomplish this approximately with:

(Max Weight/Actual Weight) * Max Weight ROC

or more precisely:

Climb Gradient % = ((Thrust-Drag) / Weight) * 100. If you don't know what the Thrust-Drag value is then you can work it back from a known ROC at a known weight.

If you know your TAS then you can convert the Climb Gradient to a ROC.

You can divide kts by 10 to convert to feet per minute or use 6080 feet per nm to convert a ROC in kts to feet.