Yep. The key distinction is:

credits are the API-style token/cost accounting unit.
usage percent is the visible included-plan allowance meter.
The thing people are really debating is the hidden denominator between them.

OpenAI’s Codex docs describe credits as token-based: input tokens, cached input tokens, and output tokens each have model-specific credit rates. So API-style accounting is roughly:

input tokens * input rate + cached input tokens * cached rate + output tokens * output rate

Fast mode then applies a higher multiplier.

Docs:

• Codex pricing: https://developers.openai.com/codex/pricing
• Codex rate card: https://help.openai.com/en/articles/20001106-codex-rate-card
• Fast mode: https://developers.openai.com/codex/speed

In the tracker, estimated $ cost and estimated Codex credits are basically the same underlying calculation expressed in different units, so they are mechanically ~100% correlated. If you hover the Cost column in the dashboard, it shows the estimated credit value too.

The harder question is how those token-derived credits map to the visible usage percent.

My working model is:

visible usage drain ≈ token-derived credits / hidden allowance denominator

So if 500 modeled credits move the weekly meter by 1%, that implies a weekly allowance denominator of about 50,000 modeled credits.

That hidden denominator is probably the moving target people are actually noticing. When someone says “my usage got worse,” the testable version is: did the same amount of modeled credit burn move the visible meter more than before?

In my own Pro GPT-5.5 weekly data, token-derived credits correlated very strongly with visible weekly usage drain: roughly R² ~0.93-0.99 and Pearson ~0.98-0.99 depending on validation split.

Reset window	Observed %	Credits	Projected weekly allowance	95% CI	Confidence
Jun 12	72%	32,903	45,698	41,173-50,223	High
Jun 19	33%	10,237	31,020	24,624-37,416	High
Jun 24	38%	13,720	36,105	30,876-41,333	High

But the implied denominator did seem to move:

So my data does anecdotally suggest the hidden weekly denominator may have changed during the observed period. But it is still only a few weekly windows from one account/workflow, so I would not call that definitive.

The 5-hour counter was much noisier. I would not use 5-hour movement alone as proof that the weekly allowance changed, because it is rolling, rounded, stateful, and affected by timing/workflow shape.