1. Slot Car Scales for Competitions
1:24 scale - is used for commercial racetracks. Cars in this scale are 7-8 inches 18-20 cm. long. Tracks are too large for normal home use.
1:32scale - (equivalent to the old #1 Gauge of toy trains) is a popular competition scale which can also be used at home on larger layouts. 1:32 is the same scale as Britains toy soldiers and figures. 1:32 Slot cars are 5-6 inches (13-15 cm.) long.
HO scales - where the cars vary from 1:87 to 1:64 scale.
2. Slot Car Scales for Home Racing
1:32 scale is fast becoming a popular choice for home racers as well as competitions. In 1:32 scale a track with a length of 37 feet will take up 8ft x 16 ft of space.
HO scales - 1:87, 1:76 (Britsh OO scale railways). The HO scales have evolved from models adapted from train scales to a car variant which takes larger motors and which is now closer in actual scale to 1:64. The cars are 2 1/2 to 3 1/2 inches long (6 to 9 cm ). Regardless of their scale size, HO cars will all run on the same width track.
O scale - Slot cars are also available in O scales similar toy train scales of 1:48, but these are an unusual size.
3. Slot Cars for Children
Children's cars and tracks are mostly marketed in 1:43 scale which is similar in size to O scale trains (toy trains). A car in this scale is 4 1/4 or 11 cm long.
Darda cars, another popular form of model car racing (wind up motor racing no electricity) are listed as being 1:43 scale but that appears to vary with the model and ranges up to 1:58 at least.
4. Track types
1:24 and 1:32 cars for competition are usually run on wood sheet tracks with routed guides for the cars and commonly have 6 8 lanes. The most often discussed track for competition 1:24 racing is the blue king track which is 155 ft. long and designed to particular shapes and standards.
HO scale competition tracks are usually 60 - 100 ft long with 4- 6 lanes. In this scale the track may be routed wood or plastic.
Children's cars for home use generally run on plastic slot together track sections.