Scales explained: 1:18 to 1:350

What the numbers mean

A scale is the ratio between the model and the real thing. In Airfix’s words, “a 1:72 scale kit therefore is 72 x smaller than the original” — and “the smaller the scale number … the larger the kit compared to the original” (Airfix). Scales are written with a colon (1:72) or a slash (1/72); both mean the same (Wikipedia).

To work out a model’s length, divide the real length by the scale number: a 15-metre jet at 1:72 is 15,000 mm ÷ 72 ≈ 208 mm. Use the calculator above to try others.

The scales you’ll meet

• 1:18 — large die-cast cars; many 1:18 cars are over 11 inches long (Wikipedia).
• 1:24 and 1:25 — car kits and die-cast. Many American car kits are 1:25, a minor variation of 1:24 (Wikipedia) — AMT’s Ford Thunderbird kits are 1:25.
• 1:32 — historically a toy “standard size”, used for slot cars, farm toys and some aircraft kits (Wikipedia). Aoshima’s and AiP’s FAB 1 kits are 1:32.
• 1:43 — a popular size for die-cast model cars; Wikipedia notes it was used from the 1950s to the 1980s by makers including Corgi Toys and Dinky Toys, with models typically 10–13 cm long (Wikipedia).
• 1:48 — popular for aircraft kits; a quarter of an inch represents one foot (Wikipedia). Several USAF Thunderbirds kits are 1:48.
• 1:72 — used most commonly for model aircraft (Wikipedia). Airfix calls it its “home scale” (Airfix); and Wikipedia says it originated with British model aircraft ranges of the 1930s. Hobby Master’s Thunderbirds die-cast jets are 1:72.
• 1:76 (OO gauge) — the UK’s most popular model railway standard, at 4 mm to the foot (Wikipedia).
• 1:144 — small aircraft and spacecraft kits (Wikipedia). AiP’s Thunderbird 1 and its new Thunderbird 2 are 1:144.
• 1:350 — used for several Thunderbirds kits (see below).

Why Thunderbirds craft come in so many sizes

The craft in the TV series range from a car to a space station, so kit makers choose a different scale for each. Bachmann’s AiP range alone runs from 1:350 (Thunderbirds 2 and 3, and Fireflash) through 1:144 (Thunderbird 1), 1:72 (the Mole) and 1:48 (Thunderbird 4) to 1:32 (FAB 1) (Bachmann). The same craft can also appear at more than one scale: AiP’s 1:350 Thunderbird 2 is 215 mm long, while its new 1:144 Thunderbird 2 is 53 cm long.

Die-cast toys often don’t follow a scale at all. Corgi lists its Thunderbirds models as “Fit the Box”, and said its 2015 Thunderbirds 1 and 3 were made to a “design scale” (Corgi) — so they won’t necessarily be in proportion with one another.

Choosing a scale

• For a display cabinet, pick one scale per collection so models sit together in proportion.
• For aircraft, 1:72 offers a wide choice of kits and die-cast; 1:48 models are larger.
• For cars, 1:43 suits a large collection on shelves; 1:18 makes a single centrepiece.