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MIDWESTAIRSOFT.SPACE

Airsoft Ballistics Calculator

Pick your gun power and BB weight, adjust the hop-up slider until the green line flies flat — then read exactly where to aim at every distance.
SYSTEM ONLINE
STD ATM: 14.7 PSI
AIR: 0.075 lb/ft³
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How to use this calculator
Enter your gun's joules and BB weight, then slide Hop-Up until the green line flies flat past 30–40 yards. The table below tells you exactly where to aim at 25, 30, and 50 yards — so you stop guessing and start hitting.
◈ PISTOL ~ 1.0J / 0.20g
◈ AEG RIFLE ~ 1.5J / 0.25g
◈ DMR / HPA ~ 2.3J / 0.28g
◈ SNIPER ~ 2.3J / 0.40g
◈ HOP-UP 50% = perfectly flat shot
◈ Parameters MOD-01
Quick Presets
J
0.1J5.0J
%
OFFNEUTRALOVER-HOP
50% = FLAT · <50% DROPS · >50% RISING
°
-10°0°+15°
mph
NEGATIVE = HEADWIND · 10 MPH = LIGHT BREEZE
°F
◈ Trajectory — 50 yd — STANDBY —
HOP-UP Set parameters and calculate
With Hop-Up
No Hop-Up
Ground
Hit Zone ±8 in
Muzzle Speed—
Effective Range—
Max Range—
50 yd Flight—
◈ Impact Data — Fixed Distances
DIST BB HEIGHT WHERE TO AIM VELOCITY ENERGY STATUS
— CALCULATE TO SEE DATA —
◈ Plain English Summary
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Set parameters and calculate.

At 25 yards —
At 50 yards —
Effective range (±8 in) —
Max range —

How the Airsoft Ballistics Model Works

Projectile Motion

The BB is treated as a rigid sphere launched at a set angle. Gravity pulls it down at 9.8 m/s² while drag slows it horizontally. Both forces are calculated in small time steps (every 2 ms) to build the full flight path you see on the chart.

Air Drag

Drag force depends on air density, the BB's cross-sectional area, velocity squared, and a drag coefficient (Cd ≈ 0.47 for a sphere). As the BB slows down, drag decreases — so it loses speed faster at the start of flight than at the end.

Hop-Up (Magnus Effect)

Hop-up puts backspin on the BB. Backspin creates a pressure difference above and below the ball — lower pressure on top pulls it upward (Magnus lift). At 50% hop-up this lift exactly cancels gravity, producing a flat shot. Below 50% the BB drops; above 50% it rises.

Muzzle Velocity from Joules

The calculator converts joules to muzzle velocity using KE = ½mv². A 0.25g BB at 1.5J leaves the barrel at about 110 m/s (360 fps). Heavier BBs fly slower from the same joule rating but retain energy better at distance.

Effective Range

Effective range is the farthest distance where the BB stays within ±8 inches (±20 cm) of your aim point — roughly the size of a person's torso. Past that point the BB has dropped or risen too far to reliably hit a target without holdover correction.

Model Limitations

This is a simplified model. It assumes calm air (no wind unless you enter it), consistent hop-up along the full flight, and standard sea-level atmosphere. Real-world results vary with barrel length, inner barrel quality, and BB roundness.

Airsoft BB Trajectory & Hop-Up Calculator

This free airsoft ballistics calculator simulates the full flight path of a BB based on your gun's muzzle energy (joules), BB weight (grams), and hop-up backspin setting. It's designed for AEG rifles, HPA guns, DMRs, and airsoft sniper rifles at any power level.

The hop-up system applies Magnus effect lift to counteract gravity. Dialing it in correctly is the single biggest factor in your effective range. This calculator shows you exactly what happens to your BB at every yard — so you stop guessing and start hitting.

Use the BB drop chart to find your aimpoint at 25, 30, 40, and 50 yards. Convert joules to FPS for any BB weight. Understand why a 0.25g BB at 1.5J performs differently than a 0.40g BB at 2.3J, even at the same effective range.

Built for the Midwest airsoft community by Midwest Airsoft Hub — your source for local airsoft fields, events, and gear guides in the Midwest.