Starting Propellor sizes are mid range pitch props that should fly just about any plane designed for that size engine. Use these first as in most cases they will be close to being the correct size. Then use trial and error to try and fne tune the maximum performance from your model by trying to alternate props. If none work better stick with the recommended starting prop.
Prop Charts
Two - Stroke Engines
| Alternate Propellors | Starting Prop. | Engine Size |
| 5.25x4, 5,.5x4, 6x3.5, 6x4, 7x3 | 6x3 | .049 |
| 7x3, 7x4.5, 7x5 | 7x4 | .09 |
| 8x5, 8x6, 9x4 | 8x4 | .15 |
| 8x5, 8x6, 9x5 | 9x4 | .19 - .25 |
| 9x7, 9.5x6, 10x5 | 9x6 | .20 - .30 |
| 9x7, 10x5, 11x4 | 10x6 | .35 - .36 |
| 9x8, 11x5 | 10x6 | .40 |
| 10x6, 11x5, 11x6, 12x4 | 10x7 | .45 |
| 10x8, 11x7, 12x4, 12x5 | 11x6 | .50 |
| 11x7.5, 11x7.75, 11x8, 12x6 | 11x7 | .60 - .61 |
| 11x8, 12x8, 13x6, 14x4 | 12x6 | .70 |
| 12x8, 14x4, 14x5 | 13x6 | .78 - .80 |
| 13x8, 15x6, 16x5 | 14x6 | .90 -.91 |
| 15x8, 18x5 | 16x6 | 1.08 |
| 16x10, 18x5, 18x6 | 16x8 | 1.20 |
| 18x8, 20x6 | 18x6 | 1.50 |
| 18x10, 20x6, 20x10, 22x6 | 18x8 | 1.80 |
| 18x10, 20x6, 20x10, 22x6 | 20x8 | 2,00 |
Four Stroke Engines
| Alternate Propellors | Starting Prop. | Engine Size |
| 9x5, 10x5 | 9x6 | .20 - .21 |
| 10x6, 10x7,11x5, 11x7, 11x7.5, 12x4, 12x5 | 11x6 | .40 |
| 10x6, 10x6, 10x8, 11x7, 11x7.5, 12x4, 12x5 | 11x6 | .45 - .48 |
| 11x7, 11x7.5, 11x8, 12x8, 13x5, 13x6, 14x5, 14x6 | 12x6 | .60 - .65 |
| 12x8, 13x8, 14x4, 14x6 | 13x6 | .80 |
| 13x6, 14x8, 15x6, 16x8, 17x6, 18x5, 18x6 | 14x6 | .90 |
| 14x6, 15x86, 15x8, 16x8, 17x6, 18x5, 18x6 | 16x6 | 1.20 |
| 15x6, 15x8, 16x8, 18x6, 20x6 | 18x6 | 1.60 |
| 18x12, 20x8, 20x10 | 18x10 | 2.40 |
| 18x10, 18x12, 20x10 | 20x8 | 2.70 |
| 18x12, 20x10 | 20x10 | 3.00 |
