Make the distance familiar
A 5 km length contains 50 straight 100 m sections. Picture a marked 100 m sprint straight repeated end to end, rather than a whole stadium lap.
Work it out, one step at a time
Turn kilometres into metres
5 × 1,000 = 5,000 m
One kilometre contains 1,000 metres. The length stays the same.
Choose a speed, then find the time
5 km ÷ 5 km/h = 1 h
At a chosen constant 5 km/h, it takes about 1 hours. This is a calculation with no stops; hills, traffic and real journey conditions are not included.
What if the speed doubles?
For the same distance and constant speed, time halves. For example, 10 km takes 2 hours at 5 km/h but 1 hour at 10 km/h.
The distance is this page’s chosen input. The speed is a teaching assumption. Time = distance ÷ speed.
Build a scale modelChoose two references and change the model size.
Build a scale model of any two lengths
Choose from all 71 Macro and 54 Micro references, or enter your own length. Set B’s model length and see A change on the same fixed metre ruler. The bars represent the stated lengths, including their different measurement definitions.
- Length ratio A / B
- Model length B
- Calculated model length A
A · Chosen distance A
5 km
A chosen input length, not a new measurement of a reference.
User / page input
The ratio follows this input assumption.
Definition and evidence reviewOriginal sourceB · Golden Gate main span
1.28 km
Main suspension span between supports, listed as 1,280 m (4,200 ft).
Source claim checked
Rounded main span, not the 2,737 m total bridge length including approaches. The two listed units are rounded, not an exact equality.
Definition and evidence reviewOriginal sourcemodel A = (A / B) × model B
This calculator uses the existing journey comparison inputs. Review-pending or conceptual entries remain illustrative inputs here; the public reviewed dataset keeps their numeric values withheld. Radius, height, diameter and experimental bound keep their individual definitions.
One distance, two very different efforts
A 5 km course takes 1 hour at a steady walking speed of 5 km/h, or 30 minutes at an assumed running speed of 10 km/h. The running speed is an illustrative calculation assumption; personal pace and training goals depend on the runner.
A course can fold back on itself
A 5K loop ends where it starts: the travelled distance is still 5 km even though the endpoint separation is zero. A runway length or mountain height is a comparison of length magnitudes; actual exercise routes require their own terrain and course measurements.
Closest ScaleTrip references
Page distance: 5 km
- Central ParkReference measurement: Length · 4 km
Ratio (page distance ÷ reference): ≈ 1.25×The north-to-south length of New York's Central Park.
- Mount FujiReference measurement: Height · 3.78 km
Ratio (page distance ÷ reference): ≈ 1.32×The elevation of Japan's symmetrical volcanic peak.
- Airport runwayReference measurement: Length · 3.5 km
Ratio (page distance ÷ reference): ≈ 1.43×The length of a runway built for large passenger aircraft.