Free Challenge Success Rate Calculator
Enter your past 75-day challenge runs and see your average days, whether you are improving, your persistence score, and which attempt is likely to be the one.
Free Challenge Success Rate Calculator
Challenge length
Days completed per attempt
Oldest attempt first. Separate with commas, spaces, semicolons, or new lines.
Add at least one attempt to see your stats.
What a challenge success rate actually measures
The classic formula is simple: completed attempts divided by total attempts, times 100. That works for one-day events. For a 75-day challenge, where almost every attempt ends early, that number tells you almost nothing useful. A first-time runner who logs 58 days has clearly done more than someone who quit on Day 4, but the binary success rate counts both as 0%.
This calculator shows the binary view (total attempts, best run, shortest run) next to an "average days per attempt" number. Average days as a share of your goal length is a more honest read on how close you are to finishing. If your average is 50 days against a 75-day goal, you are at roughly 67% of goal on every try, even if your finishes column still says zero.
Why most people take multiple attempts (and that is fine)
Most multi-day challenges use an all-or-nothing rule: miss one task on one day, restart from Day 1. That is the whole identity of programs like 75 Hard, and it is why per-attempt completion estimates float around 3%. Multiple attempts are the rule, not the exception.
Restarting is not failure. Each restart adds to your total days logged and usually bumps your average upward, which is why the persistence score in this tool gives credit for both repeated tries and longer runs. If you want to dig into restart patterns specifically, the Challenge Restart Counter breaks down which attempt broke the streak and why.
How to read your persistence score and improvement trend
The persistence score mixes two things: a logarithmic credit for showing up again, and a linear credit for how close each attempt got to your goal. Scores above 80 usually mean you have already finished a full challenge or are within a few days of doing it. Scores from 40 to 70 mean you are mid-build: the habit is forming, the runs are getting longer, and the next attempt has a real shot.
The improvement trend is an ordinary least-squares slope of your attempts over time. A positive slope (say, +3.2 days per attempt) means each restart is adding real length. A flat slope usually means one specific habit is the bottleneck. A negative slope is the loudest signal of all: stop, look at which task is breaking you, and redesign that one piece before your next try.
Track your next attempt with Reset75
Once you start your next attempt, every day, every restart, and every partial run gets logged automatically. Reset75 exports your attempt history so you can plug it back into this calculator after each run. Free download for iOS and Android, local-first, no signup. Get Reset75 to keep the next set of numbers honest.
Frequently Asked Questions
Common questions about free challenge success rate calculator
How do you calculate a challenge success rate?
The textbook way is successful attempts divided by total attempts, times 100. The problem is that almost everyone fails their first run of a 75-day challenge, so that number is mostly zeros. A more useful way to look at it is your average days completed per attempt as a share of the goal length. This calculator shows both, so you can see how close you are getting instead of just pass or fail.
What is a good persistence score for a 75-day challenge?
Above 60 means you are putting up long runs across more than one attempt. Above 80 usually means you have already finished a challenge or are within a few days of doing it. Below 40 typically means there is one specific habit (very often the second daily workout) that you need to redesign before your next try.
How many tries does it take to finish 75 Hard?
Nobody publishes a real average. 75 Hard is a 75-day challenge created by Andy Frisella, and most finishers will tell you they did not get it on the first try. Frisella himself talks about people who restart several times before finishing. The number people throw around is that about 3% of starters complete it on a given run, so needing several attempts is completely normal.
Is it normal to restart 75 Hard multiple times?
Yes. The all-or-nothing rule, where one missed task sends you back to Day 1, is the whole point of 75 Hard, the program created by Andy Frisella. Restarting is the norm, not failure. If it feels demoralizing, log every partial run in Reset75 so each restart still counts toward your persistence score.
What counts as a "successful" challenge attempt?
For most rule sets, you have to do every required habit on every day of the challenge. Anything short of the full goal is a partial attempt. This calculator treats each attempt as a number from 0 up to your goal length, so a 58-day run still counts toward your average and your persistence score.
Does my improvement trend really matter?
Yes. A positive trend (more days completed each attempt) is the best predictor that you will eventually finish. A flat or negative trend usually means one specific habit needs to be redesigned, not that you need to try harder. Use the restart counter next to this tool to see which attempts broke the streak.
Can I use this calculator for 75 Soft, 30-Day Kickstart, or a custom challenge?
Yes. Use the chip group above the goal-length input or type any custom day count from 1 to 365. The persistence score, average, and projection all scale to whatever goal length you set, so 75 Soft, 66-day habit cycles, and a 30-day reset all work the same way.
Is the success-rate calculator free? Do I need to sign up?
100% free, no signup. All your data stays in your browser via local storage. Nothing is uploaded. Clear your numbers any time with the Clear button, or copy a shareable summary with one click.