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Propeller Sizes

The propeller size should be chosen to match the engine and airframe. It may take some trial and error before you get the right propeller for your particular installation.

However, the following table may be used as a guideline for two-stroke engines with four-stroke engines in the next table.

Propeller Sizes for Two-Stroke Engines

Engine Size [cu. in.] Propeller Sizes (starting size shown in bold)
.049 5.25x4, 5.5x4, 6x3, 6x3.5, 6x4, 7x3
.09 7x3, 7x4, 7x4.5,7x5
.15 8x4, 8x5,8x6,9x4
.19 - .25 8x5,8x6, 9x4, 9x5
.20 - .30 9x6, 9x7,9.5x6,10x5
.35 - .36 9x7,10x5, 10x6, 11x4
.40 9x8, 10x6, 11x5
.45 10x6, 10x7, 11x5,11x6,12x4
.50 10x8, 11x6, 11x7,12x4,12x5
.60 - .61 11x7, 11x7.5, 11x7.75, 11x8,12x6
.70 11x8, 12x6, 12x8,13x6,14x4
.78 - .80 12x8, 13x6, 14x4,14x5
.90 - .91 13x8, 14x6, 15x6,16x5
1.08 15x8, 16x6, 18x5
1.20 16x8, 16x10,18x5,18x6
1.50 18x6, 18x8,20x6
1.80 18x8, 18x10,20x6,20x8,22x6
2.00 18x10,20x6, 20x8,20x10,22x6
Propeller sizes for two-stroke engines

Propeller Sizes for Four-Stroke Engines

Engine Size [cu. in.] Propeller Sizes (starting size shown in bold)
.20 - .21 9x5, 9x6, 10x5
.40 10x6,10x7,11x4,11x5, 11x6, 11x7,11x7.5,12x4,12x5
.45 - .48 10x6,10x7,10x8, 11x6, 11x7,11x7.5,12x4,12x5,12x6
.60 - .65 11x7.5, 11x7.75, 11x8, 12x6, 12x8, 13x5, 13x6, 14x5, 14x6
.80 12x8, 13x6, 13x8, 14x4, 14x6
.90 13x6, 14x6, 14x8, 15x6, 16x6
1.20 14x8, 15x6, 15x8, 16x6, 16x8, 17x6, 18x5, 18x6
1.60 15x6, 15x8, 16x8, 18x6, 18x8, 20x6
2.40 18x10, 18x12, 20x8, 20x10
2.70 18x10, 18x12, 20x8, 20x10
3.00 18x12, 20x10
Propeller sizes for four-stroke engines

See also: Engines, Engine Power to Weight Ratio, Propellers.