Did some research on usage limits recently. all plans included.

Plan	General impression from my tests
Plus	Fine for Luna/High, Ultra can destroy the week
Pro 5x	Generally ~5× in some tests, but surprisingly inconsistent
Pro 20x	Huge difference; parallel Max/Ultra usage becomes practical

also REMEMBER - runtime is NOT a measure of usage. and all percentages are approximate because the usage meter is rounded, so very small changes like 1–3% should not be treated as precise measurements.

So recently i've been seeing alot of posts talking about how the usage limits have been bad lately so i decided to do some experimenting.

The first month i ever got chatgpt was last month, around july 17 and i got chatgpt plus. i was able to use gpt 5.6 sol on high for around 30 minutes and that would use about 2-5% depending on how much code it changed.

then after the luna price decrease i realized that luna max was my best option. around 1 hour of luna max used 2-3% "remember this is on plus". and i also tested sol ultra and sol max, also terra max.

a 1.5 hour run of sol ultra going through a codebase and fixing bugs, adding qol features, improving stability, etc, took around 40-50% of my plus week. it launched about 6 sub agents in total and used gpt 5.5 for the subagents.

and for terra, i did a run that lasted around 1 hour and took about 15%.

sol max took about 30 minutes and used about 15%.

Now onto my 5x experience.

so recently i upgraded to pro 5x to see how the limits were, i started with 80% since i had just exhausted my plus week before upgrading. and i managed to burn around 30-40% of my week in about 1 day. i tested luna max, terra max, sol high, sol max, and sol ultra.

Luna max was honestly slightly more expensive then i expected in some scenarios, a 3 hour run took about 3% which would have been 10% on plus, but each hour on plus took around 2-5% "usually like 3" so that doesnt line up very well. luna cost around 1.5-2x more expensive on 5x *in my experience*.

Next was terra max; i gave terra a job to implement a plan that sol high had made, it took about 1.5 hours and took around 5-8% of my week. that would be about 25-40% on plus. 1.5 hours of terra max took 30% of plus. My previous 1-hour Terra Max run on Plus used about 15%, so even accounting for the extra 30 minutes, this one appeared noticeably more expensive.

And now about sol max; sol max ran for around 30 minutes, only did planning, no code changes. and took about 3-5%, that would be about 20% of plus for 30 minutes of sol max planning. this is more similar to the plus usages then the others but to be fair, it only planned.

now for sol ultra; i had it run for about 1 hour and 7 minutes, it did about the same thing i had sol ultra do on plus but this time it was on a different codebase. it used about 7-10%, i also used it for smaller fixes that you would usually use luna for, i had it fix small bugs and implement features just to test, and after about 5 prompts and another 45 minutes of working total it used about 5-7% more. this also matches up with the plus usage pretty well.

and now about the anomalies - on 5x it was going well enough to where i was wondering if they had even upgraded me but it was definitely below my expectations for certain models. until something kinda weird happened, i was just using luna max like normal and it ended up using 2% in just 30 minutes. this was extremely weird, and this was on the 5x plan btw. for reference once more, luna max would use about 3% every hour on plus, ON PLUS. this used 2% in 30 minutes on 5x. that is NOT right. and also another weird one happened, i was just using sol high for some simple planning and it used about 4% in just 30-40 minutes. that is also nooottt right.

Now onto my 20x experience.

So i got a month of 20x to test out usage limits and to code ofcourse. but instantly i went to sol ultra and gave it a pretty complex review prompt. it took 1 hour and 8 minutes, didnt change any files, and found 5 issues with the current codebase. it also launched 3 subagents and cost me 1%. "keep in mind this was another separate codebase then the past 2".

Next i wanted to test out how much 20x really held; so i launched 2 sol ultra's and 1 sol max all at once to see what would happen "and i had a couple sol high's midway through". they were all working in different repositories, #1 ultra working on security issue verification, #2 max working on designing an mls messaging recovery system, and #3 ultra planning out a big redesign for a very unfinished app. they were all launched at different times, 1 was launched first, then another was launched 10 minutes later, then another was launched 10 minutes later, and eventually they were all running in parallel.
So the first 2 ultra's only lasted about 25 minutes; 10 minutes for #3 and 15 minutes for #1, but #2 max ran for about 3 hours. i also had multiple sol high chats that were within that 3 hour time frame of the first sol ultra, the total of those sol high chats were about 30 minutes + 45 minutes + 1 hour. about 2 hours and 30 minutes of sol high total.
So all together it was as follows - 30 minutes, sol ultra. 3 hours, sol max. 2 hours and 30 minutes, sol high. multiple chats, even mid chat model changes, about 50% was planning and 50% was implementing.
All of that together charged me 5% on pro 20x
“In other words, that single ~3-hour period consumed about 5% of my 20x week, which would represent roughly an entire Plus weekly allowance if the multiplier scales linearly.”

And remember, these all were different prompts, different codebases, different instructions, different models, etc. you probably shouldn't use this as what to expect with the usage limits, everyone uses codex differently after all. but this was just my personal experience.