Compare the trip with every clock
Enter the remaining miles, a realistic average speed, expected on-duty stop time, and the balances shown on your ELD. The calculator compares driving time with the drive clock, total elapsed trip time with the 14-hour window, and expected on-duty time with the 60/70-hour cycle balance.
Use a trip average, not the truck's governed speed. Traffic, grades, construction, fuel islands, docks, and slower roads all pull the average down. If the estimate is close, a small speed change can be the difference between a workable plan and a bad one.
Break assumptions
The basic federal rule requires a qualifying 30-minute interruption after eight cumulative hours of driving without one. When CDLMath adds a separate break, it assumes that break is off-duty. It adds 30 minutes to the 14-hour timeline but does not charge it to the cycle. A break logged on-duty-not-driving can qualify under the federal rule, but that time would use cycle hours.
If you mark an entered stop as the qualifying break, the calculator assumes the stop happens before the break is due and treats the stop as on-duty time. Only check that box when the timing and duty status really fit your plan.
Reading the margin
Comfortable means every entered clock has at least 30 minutes left. Close call means the trip still fits, but the tightest margin is under 30 minutes. Not enough time means at least one clock is short. Those labels describe the estimate, not a legal ruling or a promise about traffic and parking.
This calculator handles a straightforward property-carrier trip. It does not reconstruct recaps or evaluate sleeper splits, adverse-driving conditions, short-haul exceptions, personal conveyance, Canadian rules, or carrier policy. Use the ELD and the rules that apply to the operation.