Good conduct time calculator (54 days a year)

Good Conduct Time is 54 days for each year of the sentence imposed, prorated for a partial final year, under 18 U.S.C. § 3624(b) as fixed by the First Step Act of 2018.

This calculator computes it exactly — including the proration and the day-count conventions — and subtracts it from the full-term date to produce the projected GCT release date.

Free · instant · nothing stored

See their real dates

Sentence imposed
yrs
mos

Estimates only — not legal advice. BOP makes final determinations.

Reviewed against 18 U.S.C. § 3624(b) and BOP Program Statement 5880.28. Last updated .

Why do hand calculations of good time come out wrong?

  • The 47-day ghost — pre-2019 sources describe the old 54-per-year-served math (~47 effective). Current law is 54 per year of the sentence imposed, full stop.
  • Partial-year proration — the final fraction of a year earns a prorated share, and the rounding convention matters at the day level; at least two circuits use a different proration method.
  • Jail credit interaction — GCT is computed on the sentence, but the clock position depends on credited pre-sentence time being posted correctly.
  • One year or less — those sentences earn zero GCT, which surprises people doing 12-month math.

Worked example

Quick reference: GCT ≈ sentence-months × 4.5 days

  • 30 months → ~135 days
  • 60 months → 270 days
  • 96 months → 432 days
  • 150 months → 675 days
  • Exact day counts (and circuit proration differences) are what the calculator is for.

Frequently asked questions

Is good conduct time automatic?

It's credited as earned at each sentence-year anniversary, presumed unless disciplinary findings disallow it (18 U.S.C. § 3624(b), 28 C.F.R. part 541). Projections assume clear conduct and say so.

How much good time does a 60-month federal sentence earn?

270 days — 5 years × 54 days — making the projected service about 51 months before any First Step Act credits or program time.

Can lost good conduct time be restored?

GCT disallowed through the disciplinary process is generally not restored, unlike First Step Act credits, which have a restoration path after clear conduct (28 C.F.R. § 523.43). Prevention — and challenging bad incident reports — is what matters.

Primary sources

Everything on this page is drawn from the statutes, regulations, and BOP program statements below — read them directly:

Keep reading

Estimates, not promises

This page describes federal law and Bureau of Prisons policy in general terms for education. It is not legal advice, it doesn't account for the facts of any individual case, and no attorney–client relationship is created by reading it. The BOP makes all final release-date determinations. Have an attorney review anything before you file it. Built by OutDate, the federal release date calculator.

Good conduct time calculator — 54 days per year, computed exactly · OutDate