Subathon Calculator New
Project how long your subathon will run. Pick a starting timer, sub-tier extension rules, and expected sub mix — get end time, total hours, and projected gross revenue.
Client-side only — no inputs leave your browser.
How subathons actually work
A subathon is a single uninterrupted stream whose end time is defined by the audience: each new subscription, gifted sub, and (sometimes) bits cheer or direct tip extends an on-screen countdown by a fixed number of minutes. The streamer commits to staying live until the timer hits zero or a pre-declared cap. From a math standpoint it's a queue: arrivals add airtime, the clock subtracts it, and the question is whether the arrival rate stays fast enough to keep the integral positive.
Calibrating per-sub minutes
The single most important dial is minutes added per Tier-1 sub. Five minutes (the default since Ludwig's 2021 record run) is the proven balance: visible on the timer with a single sub, dramatic with a gifted-25 raid, but slow enough that runaway growth only kicks in at sustained six-figure peak viewership. Tier 2 doubles this; Tier 3 multiplies by five. Inflexible per-T1 rates burn hosts during viral hours; bake a written downshift (e.g. "30 sec / T1 after hour 12") into the schedule so the cut feels planned. Tier 3 carries the highest revenue-per-sub on every split ($12.50 to creator on Affiliate, $17.50 on Partner). Promote it once an hour. Bits and tips are commonly accepted as extension currency at 100 bits ≈ 1 minute and $1 ≈ 1 minute; toggle them on in the calculator if your OBS overlay is wired to count them.
Cap design: Mafiathon-era defaults
Ludwig pulled off a 31-day no-cap run in 2021 and barely survived it; almost no one should try the same. Caps give the audience a clear finish line and protect voice and sleep. The post-2024 default is a 30-day hard cap (Kai Cenat's Mafiathon 2 and 3 both used it); 24-72 hours fits a smaller channel's first attempt. Pair the cap with scheduled sleep / DJ-mode blocks: 4–8 hours per 24-hour cycle reserved for guest segments or pre-recorded shows. The wall-clock projection in the calculator accounts for these. Your live-broadcast minutes compress into a longer real-world stretch.
Worked examples: Ludwig, Mafiathon 2, Mafiathon 3
Ludwig 2021 ran 5 min / T1, no cap, ended at 282,191 subs and ~31 days live. Plug "5 min/T1, no cap, 282k T1-equivalents" into the form and the math projects an impossible 1,400+ days. That's exactly why his audience-imposed soft-stop was a structural fix nothing in pure math could deliver. Kai Cenat's Mafiathon 2 (Sep 2024) finished with 728,535 peak subs under an effective ~4 min / T1 sliding rule, 30-day cap. Mafiathon 3 (Sep 2025) broke the million-sub ceiling at 1,068,000+ peak subs, averaging ~3 min / T1. Use the calculator above with these numbers. Load any of the three with the famous-subathon cards and watch the cap warning fire.
Reverse mode: solving for the audience
Most planning starts the other way around: a target length (3 days, a week, a fortnight) and the question of whether the audience can hit it. Switch the calculator to Required subs, enter the target in hours, and the math returns the T1-equivalent count needed at your chosen rate. Example: 72 hours from a 60-minute opener is 4,260 minutes to add — at 5 min/T1 that's 852 T1-equivalents, achievable as 500 T1 + 100 T2 + 30 T3 (500 + 200 + 150 = 850). Track the goal live during the stream with the Sub Goal Thermometer OBS browser source, and pair the projected gross with the Stream Revenue Estimator to see how a one-shot subathon stacks up against a normal monthly run-rate.
