Ballistic calculator: bullet trajectory and scope adjustments

An online tool for calculating bullet trajectory: drop and rise relative to the line of sight, corrections in scope clicks, wind drift, velocity and energy at any distance. The bullet drop calculator accounts for temperature, pressure, humidity and shooting angle, and for dozens of popular loads it already knows the bullet weight, muzzle velocity and ballistic coefficient from the manufacturers.

How to use it

Pick a load

From the list or type in the box data.

Set your zero

Scope height, zero range and conditions.

Read the hold

Clicks for the target and a range table.

Work out bullet drop and scope clicks for your own conditions

Load

Load from the list

Bullet weight

Muzzle velocity

Ballistic coefficient

Model

Spin drift (optional)

Twist rate, inches per turn

Bullet length, mm

Drift of a spinning bullet to the right with a right-hand twist, from the Litz formula. Without twist rate and bullet length it is not calculated.

Rifle and zero

Scope height over bore

Zero range

Zeroed above the aim point by

Click value

Conditions

Temperature

Humidity, %

Pressure

Altitude

Which pressure is this

Wind and angle

Wind speed

Wind from (clock)

Shot angle, ° (uphill +)

Units

Target distance

Table step

Table to

Vital zone for MPBR

The result is a flight model built from the manufacturer data and the conditions you enter. Confirm your holds at the range before hunting: the ammo lot, barrel and scope all add their own share.

Features

Checked against manufacturer tables

For 176 Sellier & Bellot loads the result reproduces the published table: out to 400 m velocity differs by no more than 0.2% and drop by no more than 2 mm. Against the open-source py-ballisticcalc solver the difference stays under 1 cm at 1000 m.

Loads straight from the box

6.5 Creedmoor, .308 Win, .30-06, .300 Win Mag, 7.62x39, 9.3x62, 12 gauge slugs and more: bullet weight, velocity and G1/G7 coefficients come from the manufacturers’ product pages, and every entry links to its source.

Weather for where you stand

One button fills in temperature, pressure and humidity from the forecast for your location. Air at −4 °F is 16% denser than at 68 °F, and at 400 m a .308 Win bullet drops another 9 cm.

Maximum point blank range

For a vital zone of your choice, such as 6 inches, the calculator finds the zero distance that keeps the bullet inside the zone for the longest stretch and shows where that stretch ends.

Wind, angle and spin drift

Wind is set by the clock, shooting angle in degrees for uphill and downhill shots, and with the barrel twist and bullet length it adds spin drift using the Litz formula.

Printable dope card

The table of drop, clicks, wind drift, velocity and energy saves as one PDF together with the load and the conditions it was calculated for.

What you can do

Find how many clicks to dial for a 300, 400 or 500 yard shot
Work out how far a crosswind pushes the bullet
Find the point blank range for the vital zone of your game
Compare trajectories of loads from different manufacturers
Account for cold, heat, altitude and uphill or downhill shots
Save the dope card as a PDF

How this calculator is different

A trajectory calculator that simply draws a nice curve cannot be checked by eye: a mistake in the coefficient units or the air density produces the same curve and a miss at 300 yards. So we checked our results against other people’s numbers, the Sellier & Bellot and Hornady tables and the open-source py-ballisticcalc solver, and we show the comparison right on the page: for a listed load you can see what the manufacturer prints and what we calculate. The second difference is the load data itself: every entry links to the manufacturer’s page instead of using an average BC for the caliber.

Frequently asked questions

G1 or G7: which model should I pick?

If the manufacturer gives both coefficients, use G7: for modern boat-tail bullets it is more accurate across the whole range. We checked this on Sellier & Bellot tables: with their G7 coefficient our velocities match the table within 0.2% at 400 m, while with their own G1 coefficient short flat-nose bullets drift up to 8% off. If the box only lists G1, use G1, since that number was measured for that model.

My load is not in the list. Where do I find the ballistic coefficient?

On the box, in the catalog or on the bullet’s product page, usually labeled BC G1 or G7. If the manufacturer does not publish one, start from a bullet of similar weight and shape, then refine the coefficient by shooting: adjust it until the calculated drop at 200–300 yards matches what your target shows.

Why is my rifle slower than the velocity on the box?

The velocity on the box is measured in a test barrel: 600 mm for Sellier & Bellot and 24 inches for Hornady. A shorter barrel launches the bullet slower, and at long range it shows. The most accurate fix is to measure your own velocity with a chronograph and enter it as the muzzle velocity.

How are uphill and downhill shots handled?

The distance in the calculator is the line-of-sight range your rangefinder shows, and the angle is entered in degrees, positive uphill and negative downhill. Uphill and downhill alike, gravity pulls the bullet away from the line of sight less than on level ground, so the correction on a slope is smaller than the table value. On steep slopes the calculator also accounts for the thinner air the bullet climbs into.

What does the “below Mach 1.2” warning mean?

The bullet is approaching the speed of sound, where drag changes sharply and unpredictably: dispersion grows and a coefficient measured at supersonic speed describes the flight less well. Rows where the bullet is slower than Mach 1.2 are highlighted. You can still shoot farther, but trust the numbers less.

Why is my hold different in winter at the same distance?

Cold air is denser: at −4 °F it is 16% denser than at 68 °F, so the bullet sheds speed faster. For a .308 Win 180 grain load zeroed in summer at 100 m, winter drop at 400 m is about 9 cm greater. Powder also burns slower in the cold and muzzle velocity falls. The calculator does not know that part, so it is worth measuring once with a chronograph.

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Who is this tool for?

🎣 Hunters & anglers

Published 21 Oct 2026 Author: The Supreme