Using this calculator, it is possible to calculate high winds quickly by switching between apps or using a second device.
How the High Wind Calculation works in practice
- ⬅️➡️Side winds are unaffected
- ⬆️⬇️+/-10% for headwind(-) tailwind(+)
- ↗️↘️+/-5% for headwind(-) tailwind(+) as it will affect the growth/shrink by half
The Algorithm behind the Calculations
In GR matches, the wind ring grows and shrinks with distance at a fixed of 10%, when it is over 10. The first 10 are unaffected by size change, so the calculations needed beyond that are only made concerning the additional wind.
For instance, with perfect tailwind the wind ring will shrink by 10% over 10.
In the following example, GR shows full tailwind at 17.8:
- 17.8 – 10 = 7.8 (the amount to calculate)
- 7.8 x 0.1 = 0.78 (the 10% alteration)
- 7.8 – 0.78 = 7.02 (taking that off to account for shrinkage)
- 7.02 + 10 = 17.02 (re-adding the 10mph)
Real correction will be 17.02.
This is over complicating it, but the details are necessary to explain in detail and help to understand.
Wind Correction Calculation Table
You can use the following table as a reminder, or use the automatic calculator at the beginning of this page to have a quick reply on ANY wind condition!
Full Tailwind  ️ | wind |  Full Headwind |
| 11.8 (-0.2) | 12 | 12.2 (+0.2) |
| 12.7 (-0.3) | 13 | 13.3 (+0.3) |
| 13.6 (-0.4) | 14 | 14.4 (+0.4) |
| 14.5 (-0.5 | 15 | 15.5 (+0.5) |
| 15.4 (-0.6) | 16 | 16.6 (+0.6) |
| 16.3 (-0.7) | 17 | 17.7 (+0.7 |
| 17.2 (-0.8) | 18 | 18.8 (+0.8) |
| 18.1 (-0.9) | 19 | 19.9 (+0.9) |
| 19 (-1.0) | 20 | 21 (+1.0) |
Half Tailwind  ️ | wind |  Half headwind |
| 11.8 (-0.1) | 12 | 12.2 (+0.1) |
| 12.7 (-0.15) | 13 | 13.3 (+0.15) |
| 13.6 (-0.2) | 14 | 14.4 (+0.2) |
| 14.5 (-0.25) | 15 | 15.5 (+0.25) |
| 15.4 (-0.3) | 16 | 16.6 (+0.3) |
| 16.3 (-0.35) | 17 | 17.7 (+0. 35) |
| 17.2 (-0.4) | 18 | 18.8 (+0.4) |
| 18.1 (-0.45) | 19 | 19.9 (+0.45) |
| 19 (-0.5) | 20 | 21 (+0.5) |
For those of you who like calculating by themselves, the algorithm is the following:
- FULL TAILWIND: (GRwind-10)*0.9+10
- FULL HEADWIND: (GRwind -10)*1.1+10
- HALF TAILWIND: (GRwind -10)*0.95+10
- HALF HEADWIND: (GRwind -10)*1.05+10
If, like most, you want a VERY QUICK calculation, use the automatic calculator at the beginning of the page.