How iStints turns four numbers into a complete race strategy
Enter your race duration, average lap time, fuel tank capacity, and fuel used per lap, and iStints calculates your full stint timeline, pit stop windows, and driver rotation automatically. There is no spreadsheet to build, no formula to debug, and no manual recalculation when a stint runs longer or shorter than planned.
The walkthrough below uses the real calculator, not a mockup, so what you see is exactly what you get when you start planning your own race. Every stint length, pit window, and fuel number updates instantly as soon as you change an input, so your plan always reflects your latest numbers.
iStints is free to use and works for any endurance race format, from short club sprints to twenty four hour team events, whether you race online in iRacing or in real life on track. You can start planning immediately without creating an account, then save your plan later if you want to return to it or share it with your team.
Build your plan right here
Built for every kind of endurance racer
Multi driver endurance teams
Whether you race together in iRacing or share a car in a real world endurance event, coordinating driver swaps and fuel windows across a team is hard to do from memory. iStints gives everyone one shared stint plan that updates the moment anything changes, so no driver is ever guessing when they are up next.
Solo endurance racers
Racing long stints alone means you are your own strategist, fuel calculator, and pit crew all at once. iStints gives you a personal fuel and pit stop plan you can trust lap after lap, so you can focus on driving instead of doing math mid race.
No spreadsheet skills needed
You do not need to know a single formula. Enter your race numbers into plain fields and iStints does the rest.
Any driver count
Plan for a single driver or a full multi driver roster with the same tool, with no separate setup for team size.
Race engineers and strategists
Race engineers and strategists need to coordinate pit calls and driver swaps in real time, often while watching the race unfold lap by lap. iStints gives you the same live timeline your drivers are following, so every call you make is based on the current plan rather than an outdated printout.
Any device, any time
Build your plan on a laptop before the race, then check it from a phone or tablet at the pit wall itself.
Fits your race format
Endurance, multi class, day or night racing, iStints adapts the plan to your event instead of assuming one fixed format.
Club and league racers
Club and league racers often want a simple printed sheet for the pit wall without installing dedicated software or learning a new tool. Build your stint plan online in minutes, then print it in one click so it is ready before you even leave for the track.
No installs, no downloads
iStints runs entirely in your browser, so there is nothing to install before you can start planning your race.
One tool from first draft to race day
Start with a rough plan the moment you have your race numbers, then refine driver order, stint length, and pit timing right up until the green flag. iStints stays the single place your plan lives, from that first draft through the race itself.
How iStints compares to planning it yourself
iStints versus a racing spreadsheet
Spreadsheets and manual math get harder to trust the longer a race runs, since every unplanned pit stop or slower stint means updating formulas under pressure. iStints replaces both with one guided flow that recalculates instantly, so your plan stays accurate no matter how the race actually unfolds.
- A spreadsheet someone has to build and maintain
- Manual recalculation every time a stint runs long or short
- Plan updates scattered across messages and group chats
- Retyping the same fuel and lap math after every change
- A guided set of fields any teammate can fill in
- The plan recalculates itself the instant something changes
- One live link the whole team follows
- A printable sheet ready for the pit wall
iStints versus a typical split calculator
Most split calculators only do the math and stop there, leaving you to handle the rest of race day on your own. iStints is built around the parts of race day a plain calculator cannot handle for you, from sharing the plan with your team to getting it onto the pit wall.
A shared live plan
Not just a number output sitting on your own screen. Your whole team follows the same plan as it updates in real time, so every driver and engineer sees the exact same stint timeline at the exact same moment.
A printable pit sheet
Print the finished plan for the pit wall in one click, with no extra formatting needed and no separate document to maintain. The printed sheet mirrors the plan on screen exactly, so there is never a mismatch between what your crew sees and what your drivers are following.
Calendar export for every stint
Add each stint straight to your calendar so every driver knows exactly when they are up, without anyone needing to track the timeline manually. Reminders show up wherever you already keep your schedule, so nobody misses a driver change.
No signup required to start
Start building a plan immediately with no signup, no downloads, and no waiting. Create an account only if you want to save your plan, sync it across devices, or come back and adjust it later.
Frequently asked questions about stint and pit stop planning
How do you calculate pit stops and fuel stints for endurance racing?
iStints turns your race duration, lap time, and fuel numbers into a full stint and pit stop plan automatically, the same calculation a race engineer would run by hand, done in seconds instead of a spreadsheet. The plan updates instantly whenever you change an input, so you can test different fuel strategies or driver rotations before committing to one.
Do you need to create an account to start planning a race strategy?
No account is required. Open iStints, enter your race duration, lap time, and fuel numbers, and you have a working stint plan immediately. Create an account only if you want to save and sync plans across devices, or if you want to return to the same plan later without rebuilding it.
Can iStints replace a racing spreadsheet for team strategy?
Completely. Instead of maintaining formulas and copying numbers between tabs, your whole team works from one live plan that recalculates the moment any input changes. That means no version confusion between teammates and no risk of someone racing off an outdated copy of the plan.
How accurate is an online fuel and pit window calculator?
As accurate as the numbers you put in. iStints runs the exact same lap, fuel, and pit window math a strategist would do by hand, so the plan you see is one you can trust on race day. Because the calculation is instant, you can also recheck your plan mid race if conditions change and fuel consumption shifts.
How fast can I build a complete race strategy?
Under a minute for a first draft. Enter your race duration, lap time, and fuel numbers, add your drivers, and iStints returns a full stint timeline you can refine from there. From that first draft you can adjust driver order, stint length, or pit windows in seconds until the plan matches how your team actually wants to race.
What makes a good stint and pit stop plan for a long distance race?
A good plan accounts for fuel range, driver rotation, and pit loss together, not just lap count. iStints calculates all three at once, so every stint length and pit window in your plan is grounded in your actual car and team, not a rough guess. That combination is what keeps a long race plan realistic from the green flag to the checkered flag.
Disclaimer
This tool provides race projections and estimates based on user input and standard calculations. Please keep in mind:
- Calculations and projections provided by this tool are based on a combination of personal experience, discussions with engineers, and statistical analysis of motorsport events. While every effort has been made to ensure accuracy, no guarantee is made that results are error-free or perfectly suited to your specific scenario. Use at your own risk.
- All outputs are intended as estimates and may not reflect actual race outcomes. The tool does not account for every possible variable or unforeseen event.
- You are solely responsible for how you use, interpret, and act upon the information provided. The creator and contributors of this tool accept no liability for any loss, damage, or consequences resulting from reliance on these calculations, including but not limited to race results, strategy decisions, or financial outcomes.
- Real-world variables—such as rain, yellow flags, safety car periods, driver performance, car setup, tire wear, fuel consumption, and weather conditions—can dramatically affect race results and are not fully accounted for in these projections. Motorsport is inherently unpredictable.
- Final numbers and recommendations are for guidance only and should not be considered definitive, guaranteed, or a substitute for professional engineering advice. Always consult with your team, engineers, and review all data before making critical decisions.
- This tool is continually updated based on user feedback, new data, and evolving best practices. However, it remains your responsibility to verify all results and ensure they are appropriate for your unique situation.
Any Garage61-related names, marks, services, or data referenced by this application belong to their respective owners and do not imply ownership, endorsement, or partnership unless explicitly stated.
Donations: The “Support & Donate” link opens Buy Me a Coffee (a third-party service). Donations and payments are processed by them under their terms and privacy policy. iStints does not collect or store payment details.
By using this application, you acknowledge and accept these limitations.
Local storage notice: This app stores your stint plan in your browser’s local storage (localStorage) to preserve it on this device. You can remove it anytime by clearing this site’s data in your browser settings.
Official Split Calculator for AC7 SG28 Racing
This application and all its content are the exclusive intellectual property of Cesar Cabral, the creator and mentor of this project. The original idea for this tool was to assist with iRacing endurance races, but its features and calculations are equally valuable for real-world motorsport events. Any unauthorized duplication, reproduction, distribution, modification, or commercial use—whether in part or in whole—is strictly prohibited and fully protected under international copyright and intellectual property laws. Violations, including but not limited to illegal copying, sharing, or adaptation of this software or its content, may result in severe civil and criminal penalties. Offenders may be subject to substantial fines, legal action, and liability for damages as determined by applicable law. All rights are rigorously enforced to the fullest extent possible. If you are unsure about your rights to use, share, or modify this project, please seek explicit written permission from the copyright holder before proceeding.
Open Collaboration: While the project is protected, we warmly welcome collaboration, contributions, and constructive feedback from the community. If you are interested in improving, extending, or building upon this work, please reach out to discuss partnership or contribution opportunities. Together, we can make this tool even better for the motorsport and sim racing community.
Attribution: If you use, reference, or are inspired by this project in your own work, please provide appropriate credit to Cesar Cabral and the iStints project. If your use also involves Garage61-related features, data, or integrations, please include appropriate credit to Garage61 as well.
Thank you for supporting independent development and for being part of this journey!
© CESARCABRAL.com iSTINTS.com current version v2.0.1. All rights reserved.
