HO scale dimensions
Cheat sheet for buildings and scenery at 1:87
1 cm = 0.87 m model size × 87
Scale bars: printed at 100% (not “fit to page”), they measure the real size at scale. Lay your parts on them to check.
Building
| Icon | Item | In HO | Real | 1:1 bar |
|---|---|---|---|---|
| Storey height (floor to floor) | 31 – 34.5 mm | 2.7 – 3 m | ||
| Plinth / base course | 5.5 – 11.5 mm | 0.5 – 1 m | ||
| Window (width × height) | 9 × 15 mm | 0.8 × 1.3 m | ||
| Old / mountain window | 7 × 11.5 mm | 0.6 × 1 m | ||
| Bottom of window (sill) | ~10.5 mm | ~0.9 m above floor | ||
| Top of window / lintel | ~25.5 mm | ~2.2 m above floor | ||
| Front door | 11.5 × 24 mm | 1 × 2.1 m | ||
| Barn / shed door (width) | 23 – 28.5 mm | 2 – 2.5 m | ||
| Stone wall thickness | 5.5 – 7 mm | 50 – 60 cm | ||
| Roof overhang | 5.5 – 11.5 mm | 0.5 – 1 m |
Frames
| Icon | Item | In HO | Real | 1:1 bar |
|---|---|---|---|---|
| Frame width (windows, doors) | 1.7 – 2.9 mm | 15 – 25 cm | ||
| Frame projection | 1 layer of 0.2 mm | 2 – 5 cm | ||
| Side overhang of the sill | ~0.55 mm | ~5 cm | ||
| Shutter (each leaf) | 4.5 × 15 mm | ½ window width |
Figures
| Icon | Item | In HO | Real | 1:1 bar |
|---|---|---|---|---|
| Adult man | 20 – 20.5 mm | 1.75 – 1.8 m | ||
| Adult woman | ~19 mm | ~1.65 m | ||
| Child (~10 years) | ~16 mm | ~1.4 m | ||
| Child (~5 years) | ~12.5 mm | ~1.1 m |
Vehicles
| Icon | Item | In HO | Real | 1:1 bar |
|---|---|---|---|---|
| Compact car (L × W × H) | 49.5 × 20.5 × 17 mm | 4.3 × 1.8 × 1.5 m | ||
| Small city car (length) | ~41.5 mm | ~3.6 m |
Roads
| Icon | Item | In HO | Real | 1:1 bar |
|---|---|---|---|---|
| One-way road (carriageway) | 40 – 51.5 mm | 3.5 – 4.5 m | ||
| Two-way road (carriageway) | 69 – 80.5 mm | 6 – 7 m | ||
| Motorway lane | ~43 mm | ~3.75 m | ||
| Emergency lane (hard shoulder) | 28.5 – 34.5 mm | 2.5 – 3 m | ||
| Motorway, one direction: 2 lanes + emergency lane | 120.5 – 132 mm | 10.5 – 11.5 m | too long for the sheet | |
| Pavement (width) | 17 – 23 mm | 1.5 – 2 m | ||
| Kerb height | 1.1 – 1.7 mm | 10 – 15 cm |
Street furniture
| Icon | Item | In HO | Real | 1:1 bar |
|---|---|---|---|---|
| Public bench (length) | 20.5 – 23 mm | 1.8 – 2 m | ||
| Bench: seat / backrest height | 5 / 10 mm | 0.45 / 0.85 m | ||
| Litter bin (h × Ø) | 7 × 4.5 mm | 0.6 × 0.4 m | ||
| 240 L wheelie bin (h × w × d) | 12.5 × 7 × 8 mm | 1.1 × 0.6 × 0.7 m | ||
| Yellow postbox (w × h) | 5.5 × 7 mm | 0.5 × 0.6 m | ||
| Postbox: slot height | ~12.5 mm | ~1.1 m |
Signs and posters
| Icon | Item | In HO | Real | 1:1 bar |
|---|---|---|---|---|
| Road sign (Ø) | 7 – 10.5 mm | 0.6 – 0.9 m | ||
| Bottom of sign above the pavement | ~24 mm | ~2.1 m | ||
| Sign post (Ø) | ~0.7 mm (brass wire) | ~6 cm | ||
| Portrait poster (standard size) | 10.5 × 15 mm | 0.9 × 1.3 m | ||
| Large landscape poster | 31 × 15 mm | 2.7 × 1.3 m | ||
| Large billboard | 46 × 34.5 mm | 4 × 3 m |
Fences and access
| Icon | Item | In HO | Real | 1:1 bar |
|---|---|---|---|---|
| Railing / balustrade | 11.5 – 12.5 mm | 1 – 1.1 m | ||
| Garden fence | 9 – 14 mm | 0.8 – 1.2 m | ||
| Stair step: rise | ~2 mm | ~17 cm | ||
| Stair step: going | ~3.5 mm | ~29 cm | ||
| Outdoor stairs (width) | ~11.5 mm | ~1 m |
One step ≈ 2 mm: stack strips of 2 mm styrene, setting each one back by 3.5 mm.
Indicative values: they vary by region and period. For a mountain house, favour small windows, a pronounced stone plinth and a deep roof overhang. One layer of 0.2 mm styrene gives about 2 cm of real projection at 1:87.