SplitSleeperCalc

This is an educational calculator, not an ELD, not legal advice, and not an official FMCSA compliance determination.

How this calculator reaches a verdict

SplitSleeperCalc is deterministic: the same two rest periods always produce the same answer, with no clock, no locale, no randomness and no network access. This page documents how the check runs, in the order it runs. The check itself is on the split sleeper berth calculator home page.

How the check runs

  1. Read both periods. Each needs a status, a start, an end and an explicit fixed UTC offset, so that no local time has to be guessed.
  2. Convert every time to whole minutes on one absolute line, then sort the two periods into chronological order whichever way you typed them.
  3. Reject anything contradictory: an overlap, an end before its start, a missing offset, an impossible date or time, or a log shape with more than two rest segments.
  4. Test both pairing assignments and both single-period reset readings, condition by condition, and report the result of every condition.
  5. Rank the branches that are available using the published total order, and keep all of them on screen.
  6. Quantify remaining hours only where a restart point is documented and the duty log after it was reported as unbroken driving and on-duty time.

Arithmetic and fail-closed policy

All arithmetic is whole minutes, so a period of 6 hours 59 minutes never rounds up into a qualifying 7-hour leg. Missing, malformed, overlapping or ambiguous input, including a missing UTC offset, returns an insufficient-information verdict with the reason, never a guessed result.

The 6/4 and 5/5 splits are limited 2026 Flexible Sleeper Berth pilot options for approved test participants. The rule engine does not model them, this calculator does not offer them, and a 6-and-4 or 5-and-5 pattern is never reported as qualifying.

How qualifying treatments are ranked

When more than one branch is available, valid branches are ranked by a published total order, so the same input always yields the same list:

  1. A branch whose documented restart point matches the work-total anchor you chose ranks first, because only that branch can be quantified here.
  2. A reset branch ranks above an ordinary pairing branch, because the reviewed pages state an explicit restart for a qualifying 10-hour rest but not for a paired split.
  3. A later restart point ranks above an earlier one; a branch with no documented restart point ranks last inside its group.
  4. A longer total qualifying rest ranks above a shorter one.
  5. The branch identifier in ascending order breaks any remaining tie.

Update policy

The rule text behind this build was reviewed against the four FMCSA pages below on 2026-08-25, and each source carries its own publication marker so you can see how fresh it is. Rule changes are applied by re-reading the primary sources and re-running the test suite; the calculator is not updated from secondary commentary. If a source has moved on since the date shown, treat this page as stale and read the FMCSA source directly.

Official FMCSA sources

  1. FMCSA - Hours of Service FMCSA page last updated 2026-03-26 https://www.fmcsa.dot.gov/regulations/hours-of-service
  2. FMCSA - Summary of Hours of Service Regulations FMCSA page last updated 2022-03-28 https://www.fmcsa.dot.gov/regulations/hours-service/summary-hours-service-regulations
  3. FMCSA guidance - pairing a 10-consecutive-hour rest that includes 7 consecutive sleeper hours FMCSA guidance effective 2026-07-01 https://www.fmcsa.dot.gov/regulations/hours-service/can-driver-pair-rest-period-10-consecutive-hours-includes-7-consecutive
  4. FMCSA guidance - 3 hours off duty followed by 10 consecutive hours in the sleeper berth FMCSA guidance effective 2026-07-01 https://www.fmcsa.dot.gov/regulations/hours-service/if-driver-takes-3-hours-duty-and-then-10-consecutive-hours-sleeper-0

See the method applied to real shapes: the split sleeper berth calculator ships worked 7/3, 8/2 and 3/10 examples alongside the live check.