This Javascript calculator might be useful to a slotcar hobbyist who wants to see their lap time data as Miles Per Hour (or Kilometers Per Hour). In addition, the calculator shows how long your 1:32 or 1:24 lane would be in real world miles/kilometers (but not how deep you'd have to dig the trench for the slots). I've filled in some sample data so you can press the button to see how it works; obviously you'd want to use your own data.

Input 1:32 Scale 1:24 Scale Instructions
Lane Length Feet
1:1 Scale Miles

1:1 Scale Kilometers

1:1 Scale Miles

1:1 Scale Kilometers

  • Enter the length of a lane of 1:32 or 1:24 scale track. (This is often specified in layout design programs.)
  • You can enter the feet as decimals instead of using feet and inches. (Sorry, metric isn't supported...)
  • Enter the time it takes for your slotcar to run one lap in that lane.
  • Click the "Calculate" button.
  • Duh. Put your head down.
Lap Time Time, in seconds




This is a really simple calculator, and folks with fewer damaged brain cells than I could probably do it all in their heads. However, it does save you the trouble of converting feet and inches to decimal inches, multiplying that by 32 (1:32 scale) or 24 (1:24 scale), and converting that to miles (according to Google, there are 63360 inches in a mile). It also helps to know that there are 3600 seconds in an hour (yep, I counted them all): 3600/(your laptime) gives you the multiplier for figuring out how far your car, at 1:1 scale, would have gone in an hour if you hadn't flipped it over and died 70 times from going around curves too fast.

Many folks have computer laptimers which tell you this stuff, but some programs only save the time data. Time data is great for a relative comparison of slotcars running on the same track, but it's somewhat meaningless to other folks who have tracks of different lengths and configurations. The MPH data ties both the time and the distance data into one neat number which can be more universal for comparisons. It does not however, give you any indication of the layout's difficulty or the driver's aptitude-- which can vary greatly.

The MPH figures can be compared to the real-world car, for example:

1970 Le Mans average speed, fastest lap time (Vic Elford, Porsche 917): 152 mph
1970 Porsche 917LH top speed: 239 mph
1970 Ferrari 512 S top speed: 211 mph

(Bear in mind that your lap time is average speed, not top speed. Most layouts have curves, which bring the top speed MPH down.)

1:32 slot cars may look in-scale, but they tend to stray beyond the outer fringes of realistic, in-scale speed, especially for cars with heavy magnets. Magnets can make slotcars' average lap speeds look more like the real-world's top speeds because those slotcars don't have to slow down much for curves. On the other hand, most 1:32 magnetless slotcars driven moderately can routinely surpass real world records for average speed/fastest lap time. I guess you have to make allowances though, since our view of the proceedings are somewhat god-like, and cars seem to move sooooo slowly when you're flying above them in a plane. Try running a lap at 60 MPH and you'll see what I mean. Close 'nuff...