FAQ

License Activation

BurnSim runs unlicensed as a trial - up to 25 simulations per session, resetting every time you relaunch it, with no time limit on how long you can keep doing that. When you're ready to activate (see Activating BurnSim for the full walkthrough, including offline activation and moving to a new computer):

1. Open Help > Activate...
2. Enter the email address you purchased with (or your school email if you're eligible for the free .edu license - see below)
3. Leave the optional License key box blank unless you bought BurnSim through a reseller and were given a key - a purchase direct from burnsim.com doesn't use one
4. Click Activate

What happens next depends on your license status:

• Activation successful - you're done, BurnSim is fully licensed on this machine
• Check your email - a validation link was sent to the address you entered; click it, then reopen the Activate dialog (or click Activate again) to finish
• Email validated but no license found yet - if you just purchased, activation can take up to one business day to show up. If it's been longer than that, contact burnsim@burnsim.com
• Installs used up - your license already has five computers activated. There is no limit on how many times you install BurnSim; the limit is on how many computers are active at once. You can free up a slot yourself at licensing.burnsim.com/installs.php, which lists the computers currently using your license so you can release the ones you no longer use. Contact burnsim@burnsim.com if you need more than five active installs

For anything activation-related that isn't covered above, contact burnsim@burnsim.com.

Purchasing & Downloading

BurnSim is $49 for a personal license: non-commercial use by one individual, or $149 for a commercial license covering business and professional use by one named user. Either one may be used on up to five computers at a time. Purchase at www.burnsim.com/purchase.aspx.

Using BurnSim commercially? Paid engineering, consulting, product development, research, testing, or other business use needs a commercial license - the personal and educational prices do not cover it. A commercial license is $149 for one named user and can be bought directly at www.burnsim.com/purchase.aspx. For multi-user, volume or site licensing, contact burnsim@burnsim.com. The full terms for all three license types are on the License page.

.edu users get BurnSim for free - there's nothing separate to buy or redeem. Just activate (see License Activation above) using your school .edu email address and the license is issued automatically.

The latest installer and portable builds are always available from the download page.

Installing on a Mac? macOS requires one Terminal command before BurnSim will open, and reports the app as "damaged" if you skip it - nothing is wrong with the download. Installing on macOS has the step and what the other error messages mean.

Getting Started

New to BurnSim? Getting Started with a Basic Simulation walks through building a simple motor from scratch, start to finish. BurnSim Fields is the field-by-field reference for everything on the main window once you're past the basics.

Still Running BurnSim 3?

BurnSim 3 is retired. As of September 2026 it is no longer available for download and is no longer developed. If you already have it installed it keeps working, and your license still activates - but BurnSim 4 is where everything new happens, and it is a free upgrade for existing license holders: activate it from Help → Activate... with the same details you registered BurnSim 3 with. It installs alongside BurnSim 3 rather than replacing it, and leaves your saved motors and propellant database alone.

This wiki documents BurnSim 4. BurnSim 3's interface differs substantially - the old documentation is kept for reference under BurnSim 3 (Legacy).

Other Questions

Not seeing your question here? Contact burnsim@burnsim.com - this page will grow as questions come up.