Exhaust math, jetting, trails, ride logs. Built by riders, not marketers.
That's it. One input based on your port timing and RPM target.
Header, diffuser, belly, stinger — every measurement calculated from Neels theory.
One-click copy to clipboard. Shareable URL so you can send it to your welder.
Punch in your tuned length, get all 7 pipe sections and 6 diameters back. Shareable URL so you can send it to your buddy at the shop.
Open calculator →Altitude, temp, and your current setup — get the right main jet and needle position without the guesswork. Less fouling, more ripping.
Open calculator →Log your rides and track when you last swapped the top end. One place for mileage, mods, and the stuff you'll forget in six months.
In the worksThe exhaust calculator is free, fast, and doesn't need your email address. More tools on the way — jetting next, then ride logs.