Freefall Time
Calculator

How to Use the Calculator

1. 1

   Set your deployment altitude

   The "Deploy Alt" field defaults to 4,000 ft — a common opening altitude. Change it if your dropzone or discipline uses something different. This applies across all your rows.

2. 2

   Add a row for each discipline

   Select your discipline, enter the exit altitude you typically jump from, and enter your jump count. The calculator shows freefall time per jump and total time for that discipline immediately.

3. 3

   Add more disciplines

   Hit "+ Add Discipline" for each additional discipline in your logbook. The stat bar at the top updates with your combined totals in real time.

4. 4

   Share your result

   Hit "Share" to copy a link to your exact setup. Send it to another jumper and compare who's spent more time in the sky.

Why Freefall Time Varies by Discipline

The simple version: different disciplines have different terminal velocities, and terminal velocity determines how quickly you eat through altitude. A belly skydiver reaches around 120 mph. A head-down freeflyer can push past 160 mph. A wingsuit pilot, using the wing to generate lift, may only descend vertically at 50 mph — which is why wingsuit jumps feel so long compared to a freefly jump from the same plane.

It's not just about terminal velocity either. Every skydiver starts from zero and accelerates — it takes roughly 10 seconds to approach terminal, and during those 10 seconds you're covering significantly less altitude than you will be by the time you've settled in. This calculator models both phases: the acceleration ramp and the terminal phase. For short jumps — hop and pops at 4,000–5,000 ft — you may never actually reach terminal, and the maths reflects that.

Fall Rates Used in This Calculator

These are approximate averages. Actual fall rates vary with body size, suit, equipment, and technique. The calculator gives a solid estimate — not a logbook replacement.

Frequently Asked Questions

How long is a typical skydive in freefall?

From a standard 14,000 ft exit with a 4,000 ft deployment, a belly-to-earth skydiver gets around 60–65 seconds of freefall. Head-down freeflyers fall faster and get closer to 45–50 seconds from the same altitude. Wingsuit jumpers fall much slower and typically jump from higher — from 15,000 ft they can get 2.5 minutes or more.

Why is freefall time different for different disciplines?

Each discipline has a different terminal velocity. A belly skydiver reaches around 120 mph. A head-down freeflyer can hit 160 mph or more. A wingsuit pilot, with a large wing area generating lift, may only fall at 50 mph vertically. Faster fall rate means less time in freefall from the same altitude.

What is a hop and pop in skydiving?

A hop and pop is a jump where you exit at a low altitude — typically 3,500 to 5,500 ft — and deploy your parachute almost immediately. At these altitudes there's very little time to reach terminal velocity. This calculator accounts for that: if your exit minus deployment altitude is small, the physics switches to an acceleration-only model.

How does the calculator handle terminal velocity?

The calculator uses a two-phase model. In the first phase — roughly the first 10 seconds — a skydiver accelerates from zero to terminal velocity, covering a distance that varies by discipline. In the second phase, they fall at constant terminal velocity. For hop and pops where that acceleration distance exceeds the available altitude, pure kinematic equations are used instead.

Can I add multiple disciplines to the calculator?

Yes — that's the whole point. Most experienced skydivers have jumped more than one discipline. Add a row for each: belly, freefly, sit flying, tracking, or wingsuit. Set the exit altitude and jump count for each. The calculator totals everything and shows your combined freefall time.