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Speed distance time calculator

Solve a constant-speed passage-time exercise using nautical miles and knots. Distinguish speed over ground from speed through water before applying the relation.

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The method

Distance = speed × time. A knot is one nautical mile per hour; 1 nmi = 1,852 m.

Before using the result

  • Use consistent distance/speed basis, normally speed over ground for passage time. Constant speed; no current, weather or route model.

Worked examples

These original training examples illustrate the method for USCG Captain's License (OUPV/Master). Use the matching “Load example” button above to explore a variation; example values are not equipment settings or prescribed criteria.

1. Worked example

Solve a constant-speed passage-time exercise using nautical miles and knots. Distinguish speed over ground from speed through water before applying the relation.

Solve for
Time
Distance
10 nmi
Speed over ground
10 kn
  1. Solve for time; other target input is ignored.
  2. 18520 m = 5.144444444444445 m/s × 3599.9999999999995 s.
  • Distance: 18,520 m
  • Speed: 5.144444 m/s
  • Time: 3,600 s

2. Comparison example

Compare a different supplied condition using the same method. For Marine Exam, the important check is that the input meaning, units and method assumptions still match the problem.

Solve for
Time
Distance
15 nmi
Speed over ground
10 kn
  1. Solve for time; other target input is ignored.
  2. 27780 m = 5.144444444444445 m/s × 5400 s.
  • Distance: 27,780 m
  • Speed: 5.144444 m/s
  • Time: 5,400 s

Check your understanding

1. Which relationship is used?

Distance = speed × time. A knot is one nautical mile per hour; 1 nmi = 1,852 m.

2. Which assumption should you check first?

Use consistent distance/speed basis, normally speed over ground for passage time. Constant speed; no current, weather or route model.

3. How should you verify a different unit system?

Convert every input to the displayed calculation units first. Equivalent physical inputs must give equivalent results; a unit label alone does not convert a number.

Continue with the matching exam topic

This tool connects to USCG Captain's License (OUPV/Master) free practice. Work through a question independently, then use the calculation steps to identify where your method differs. The tool stays free whether or not you choose paid preparation.

Speed distance time calculator — free with working | Marine Exam