Rifle Effective Range Calculator
Calculate the maximum effective range for any rifle caliber based on bullet energy retention and velocity at distance.
For sport shooting and ballistic study.
Maximum ethical hunting range is the distance at which a bullet retains enough energy and velocity for a clean, humane kill. It is not the maximum distance you can shoot. Accuracy, field conditions and hunter skill all matter, and in practice they bind long before energy does.
Minimum retained energy thresholds (at target):
- Deer-sized game: 1,000 ft-lbs
- Elk / large deer: 1,500 ft-lbs
- Moose / bear: 2,000 ft-lbs
Simple velocity-based range estimate: A typical hunting bullet loses roughly 25 to 35% of its velocity over the first 300 m. A low-drag match bullet loses closer to 20%, a blunt or light one closer to 40%.
Energy is proportional to velocity squared, which is why the energy curve falls so much faster than the velocity curve:
- 20% velocity loss leaves 64% of the energy
- 30% velocity loss leaves 49%
- 40% velocity loss leaves 36%
Work an actual cartridge through it. A .308 Win 150 gr leaves the muzzle around 2,820 fps carrying about 2,600 ft-lbs. At 300 m it is doing roughly 1,940 fps, which is about 1,250 ft-lbs, not far above the deer threshold and well under the elk one. Fit a heavier, higher-BC bullet and you get closer to 1,700 ft-lbs at the same distance. That spread is what the ballistic coefficient input below is for.
Practical limits also include:
- Wind drift: a 10 mph full-value crosswind pushes a .308 Win roughly 25 cm off at 300 m, and well over a metre at 600 m. Wind, not energy, is what usually ends the shot
- Bullet drop: a .30-06 zeroed at 200 m is about 80 cm low at 400 m
- Target size: a deer vital zone is around 20 cm, so the group you can hold in the field matters more than the number this page prints
- Hunter skill and position: prone from a rest is very different from offhand in field conditions
“MPBR” (Maximum Point Blank Range): The range at which you can hold dead-on a 20 cm vital zone without holdover. Typically 200–300 m for most deer cartridges.
Always practice at the ranges you intend to hunt, in field conditions, before the season.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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