How the split sleeper berth rule works
The split sleeper berth provision is the single most misunderstood part of the federal hours-of-service rules, and it is also the most useful once it clicks. In plain terms, it lets you break the 10 consecutive hours off duty you normally need into two separate rest periods, so you can rest when it makes sense for your load, your parking, and your body clock instead of all at once. The catch is that the two periods have to fit a specific shape, and if they do not, you do not get the benefit. This planner exists to show you that shape and to draw the clocks so you can see, before you turn a wheel, whether your plan actually works.
The two clocks you are always running
Every driving shift runs two clocks at once. The 11-hour clock (49 CFR 395.3(a)(3)(i)) is your total driving time. The 14-hour clock (49 CFR 395.3(a)(2)) is your window: once 14 consecutive hours have passed since you came on duty, you cannot drive again until you reset, no matter how much of the 11 you have left. Ordinary breaks, meals, and off-duty time do not stop the 14-hour clock. That is the whole reason the split matters: a qualifying split is one of the only ways to stop pieces of that window from counting.
What makes a split valid
Under 49 CFR 395.1(g), a valid split for a property-carrying driver is made of two rest periods. One must be at least 7 consecutive hours in the sleeper berth. The other must be at least 2 consecutive hours, spent either off duty or in the sleeper berth. Together the two periods must add up to at least 10 hours. That is why 7/3 and 8/2 are the pairings you hear about most: 7 plus 3 is 10, and 8 plus 2 is 10, and in each case one of the periods is a 7-hour or longer sleeper stint. A 6/4 split fails, because neither period reaches 7 sleeper-berth hours. A 9/1 split fails too, because the 1-hour period is under the 2-hour floor.
Why a valid split gives you time back
Here is the part that feels like magic until you see it drawn. When you complete a valid pair, 49 CFR 395.1(g)(1)(iii) says two things happen. First, your 11-hour and 14-hour limits are re-calculated from the end of the first of the two rest periods, not from the start of your shift. Second, the qualifying rest periods themselves do not count against the 14-hour window. The practical effect is that the driving you did before that first rest period drops off your window, and you can often keep driving when a single short break would have left you stuck. On the timeline above, this is the moment the amber window line drops: that drop is your hours coming back.
The 30-minute break still applies
A split does not excuse you from the 30-minute break rule. Under 49 CFR 395.3(a)(3)(ii), you cannot drive if more than 8 hours of driving time have passed without at least one consecutive 30-minute interruption. The good news is that the interruption can be off-duty, sleeper-berth, or on-duty-not-driving time, and any qualifying rest period in your split easily covers it. The planner tracks your driving since your last break and warns you before you hit the 8-hour mark.
Use this as a plan, not a logbook
One more time, because it matters: this is a planning aid, not a compliance record. It does not know your real duty status, whether you qualify for a short-haul exception, or how your carrier configures your logs. Your Electronic Logging Device is the authoritative account of your hours, and it is what roadside enforcement will read. Sketch your shift here, understand the shape of your split, and then confirm every number against your ELD before you drive.