Wind Drift & Shot Angle Compensator
Crosswind holds by range in inches, MOA and mils, with clock-value wind and the uphill and downhill cases — plus why wind is the hardest variable.
Reading the wind, and the hill
Clock values: only the crosswind component pushes the bullet, so a 45° wind counts about 71% and a straight head- or tailwind barely moves it laterally at all. Angled shots: shooting steeply uphill or downhill, gravity only acts over the horizontal distance — so both cases hit HIGH if you hold for the slope range. The table's "hold as" column is that corrected distance (the rifleman's rule).
Drift is computed by integrating the G1 drag model — validated in this site's tests against published figures (≈7″ at 300 yd and ≈21″ at 500 yd for a 10 mph full-value wind on a .308 168 gr). Wind is the hardest variable in shooting because it is never one speed the whole way: mirage, grass and treetops at mid-range tell you more than the flag at your muzzle. Treat these numbers as the starting hold, and let impacts teach you the rest.
How to use
- Enter wind speed and direction as a clock value.
- Set your range and load details.
- Read the hold in your preferred unit.
- Read the wind at the target, not just at your position.
Frequently asked questions
What is a clock value?
A way of expressing wind direction relative to your line of fire, with 12 o'clock straight ahead. Wind at 3 or 9 o'clock is full value and produces maximum drift; wind at 12 or 6 produces almost none. Angled winds fall between, at roughly half value at the 1, 5, 7 and 11 positions.
Why is wind harder than drop?
Because drop is predictable and wind is not. Gravity is constant and calculable; wind varies along the entire flight path, and the wind at your position may be nothing like the wind halfway to the target. Reading it correctly is what separates shooters at distance, and no calculator can do it for you.
Where along the path does wind matter most?
Nearer the shooter, counterintuitively. Wind acting early has the whole remaining flight to push the projectile off course, while wind near the target has little time to act. This is why the conditions between you and the target matter more than those at the target itself.
Does drift scale linearly with distance?
No — considerably faster. Doubling the range more than doubles the drift, because the projectile is both exposed for longer and travelling more slowly by then. This is why wind becomes the dominant error source as distance grows while drop remains merely a known correction.
How do I estimate wind speed without a meter?
By observation, roughly. Leaves and light flags move at a few miles per hour, small branches at ten, larger branches and dust at fifteen to twenty. Mirage viewed through a spotting scope is more sensitive still and is what many competitive shooters actually use.
Does uphill and downhill shooting affect wind?
Less than it affects drop. Angled shooting reduces effective gravity drop because only the horizontal component counts, which is the well-known rifleman's rule. Wind drift is affected mainly by whether terrain is channelling the wind, which is a reading problem rather than a maths one.
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