Exterior ballistics / live atmosphere

Ballistics calculator

A technical planning utility for modeling trajectory from projectile, zero, range, and local conditions. Load the latest nearby U.S. weather observation by ZIP code or GPS coordinates.

INPUT DECKUS customary units

01 Projectile

Bullet weight gr Caliber in Muzzle velocity fps Ballistic coefficient BC Drag model standard Sight over bore in

02 Shot

Zero range yd Target range yd · max 2,000 Direction of fire ° true Wind from clock

The chart and range card extend to the selected target, up to 2,000 yd. Direction of fire converts reported wind direction to clock value; 12 is a headwind and 3 is from the right.

03 Live weather

U.S. ZIP code

Official NWS data · U.S. locations only

Temperature °F Humidity % RH Pressure inHg Pressure type reference Altitude ft MSL Wind speed mph

Nearby station data can differ from conditions at the firing point. Review and edit every loaded value before use.

FIRING SOLUTION600 yd

ZERO RANGE100 yd

ELEVATION4.73 mil16.26 MOA

47 clicks at 0.1 mil

WINDAGE— 0.00 mil— 0.00 MOA

0 clicks at 0.1 mil

Terminal velocity1,633 fps

1,036 ft·lbf

Time of flight0.874 s

To target

Density ratio0.997

Relative to ICAO standard

Wind0.0 mph

From 3.0 o'clock

DIALED TRAJECTORY

Projectile path relative to line of sight

Vertical / horizontal · inches

RANGE CARD

Modeled flight data

Dialed for selected target

Range	Path	Velocity	Time
0 yd	-1.75 in	2,600 fps	0.000 s
0 yd	-1.68 in	2,599 fps	0.000 s
20 yd	2.44 in	2,564 fps	0.023 s
40 yd	6.42 in	2,528 fps	0.047 s
60 yd	10.18 in	2,493 fps	0.071 s
80 yd	13.72 in	2,457 fps	0.095 s
100 yd	17.03 in	2,422 fps	0.120 s
120 yd	20.10 in	2,388 fps	0.144 s
140 yd	22.93 in	2,353 fps	0.170 s
160 yd	25.50 in	2,319 fps	0.195 s
180 yd	27.82 in	2,285 fps	0.222 s
200 yd	29.87 in	2,251 fps	0.248 s
220 yd	31.65 in	2,218 fps	0.275 s
240 yd	33.14 in	2,185 fps	0.302 s
260 yd	34.34 in	2,152 fps	0.330 s
280 yd	35.25 in	2,119 fps	0.358 s
300 yd	35.84 in	2,087 fps	0.386 s
320 yd	36.12 in	2,055 fps	0.415 s
340 yd	36.06 in	2,023 fps	0.445 s
360 yd	35.67 in	1,991 fps	0.475 s
380 yd	34.92 in	1,960 fps	0.505 s
400 yd	33.81 in	1,929 fps	0.536 s
420 yd	32.33 in	1,898 fps	0.567 s
440 yd	30.47 in	1,868 fps	0.599 s
460 yd	28.20 in	1,837 fps	0.632 s
480 yd	25.52 in	1,807 fps	0.664 s
500 yd	22.42 in	1,778 fps	0.698 s
520 yd	18.88 in	1,748 fps	0.732 s
540 yd	14.88 in	1,719 fps	0.767 s
560 yd	10.41 in	1,690 fps	0.802 s
580 yd	5.46 in	1,661 fps	0.838 s
600 yd	0.00 in	1,633 fps	0.874 s

MODEL NOTES

Assumptions and limits

Point mass Numerical G1/G7 drag, gravity, air density, and a steady 3D wind vector. Spin drift, Coriolis, aerodynamic jump, and inclination are not modeled.

Atmosphere Station pressure is preferred. If sea-level pressure is entered, altitude converts it to estimated station pressure before density is calculated.

Weather ZIP coordinates are approximate and observations come from the nearest reporting NWS station. Conditions at the muzzle may differ materially.

SAFETY / VALIDATION

This is an engineering estimate, not a firing authorization or substitute for a verified ballistic solver, confirmed DOPE, direct weather measurement, qualified supervision, or a controlled range. Always positively identify the target, foreground, and backstop.