How Many Litres Should a Steel Safe Be? Interior Capacity and Size Guide
How is a safe's interior capacity calculated in litres, and which size suits what? We ranked Mühlen models from 5 to 390 litres by capacity and weight.
Short answer: A safe's size is determined by its interior capacity (litres) and interior dimensions, while exterior size and weight increase with insulation, body thickness and fire rating. As a general guideline (a usage recommendation, not product page data): 5–20 litres suit passports, cash and small valuables; 20–40 litres suit documents and jewellery; 60–120 litres suit regular paperwork and storing many different items; and 146 litres and above suit archives and long items. Below we have listed, from smallest to largest, the litre values stated on the product pages of the Mühlen models, and shown how litres are calculated from dimensions.
How Are Litres Calculated?
Multiply interior width × interior depth × interior height (cm) and divide by 1,000. Examples from the product pages:
- MP 53B: 38.6 × 32.5 × 31.5 cm ≈ 39.5 litres; the page says "40 litres".
- MR 140A: 117 × 60 × 47 cm ≈ 330 litres.
- Panzer CK70: 34 × 34.3 × 57.2 cm ≈ 67 litres; the page says "70 litres".
As you can see, on some models the litre value on the page differs by a few litres from the value calculated from the interior dimensions (rounding or the manufacturer's declaration). When comparing, go by the interior dimensions on the product page; litres are an approximate classification.
Size Groups and Mühlen Models
| Group | Interior capacity | Models (value on the product page) |
|---|---|---|
| Very small | 5–17 litres | Fire Bag YG75 5 L · YG85 7 L · Schutz 17W / 17B 7 L · Fire Bag YG2017 7 L · YG2030 10 L · YG2037 17 L |
| Small | 20–33 litres | MP 36B / 36W 20 L · MR 33A 20 L · Schutz 25-LB 22 L · Panzer CK26 26 L · H43-HQ 31 L · H-43 TA 33 L |
| Medium | 37–74 litres | Fire Safe 2092 37 L · MP 53B/53K/53W, MR 53A 40 L · MR 63A 50 L · Fire Safe 2096 56.5 L · MR 72A 61 L · Schutz 45P / 50P 67 L · Panzer CK70 70 L · Shutz 50 T 74 L |
| Large | 90–146 litres | Schutz 60-T / 60P 90 L · MR 85A 94 L · MR 100A 116 L · Schutz 80-T / 80P 116 L · Schutz 100P 146 L |
| Extra large | 210–390 litres | MR 122A 210 L · MR 140A 330 L · MR 171A 390 L |
Litres and Weight Increase Together
As a safe gets bigger, its weight rises quickly; this affects transport and placement planning. Some examples from the product pages: MP 36B 33 kg (20 litres), MP 53B 68 kg (40 litres), MR 85A 144 kg (94 litres), MR 140A 334 kg (330 litres). For heavy safes, check the floor load capacity and the transport route in advance; anchoring the safe should also be planned together with its size.
4 Questions When Choosing a Size
- What will you store? A4 paper is 210 × 297 mm. Since the interior dimensions of the MP 36B are (H) 237 × (W) 337 × (D) 242 mm, A4 documents fit lying flat; for files or folders, a larger interior capacity is needed.
- How much will it grow? Paperwork and belongings accumulate over time; think of the next size up from what you need.
- What is the interior layout? Shelves, drawers and a locked inner compartment divide the usable space. For example, the Schutz 60-T has 3 compartments and a separately keyed compartment; in our how to choose a home safe article we also look at shelf layout.
- Is a fire rating needed? Because fire-resistant models have a special heat-insulated interior structure, their interior capacity is generally smaller for the same exterior size (how long a fire-resistant safe lasts).
Frequently Asked Questions
How many litres should a steel safe be?
As a general guideline: 5–20 litres suit passports, cash and small valuables; 20–40 litres suit documents and jewellery; 60–120 litres suit regular paperwork and storing many different items; for archives and long items, look at 146 litres and above. These ranges are a usage recommendation, not product page data.
Which safes does A4 paper fit in?
The interior dimensions of the MP 36B and MR 33A (237 × 337 × 242 mm) allow A4 paper to be placed lying flat. For files and folders, check larger models (40 litres and above) against the interior dimensions on the product page.
How is a safe's litre capacity calculated?
Multiply interior width × interior depth × interior height (cm) and divide by 1,000. Because of rounding, the value on the product page may differ from the calculated one by a few litres.
Is a bigger safe more secure?
No; size and security are not directly related. Security is determined by body and door thickness, lock structure, alarm and anchoring.
How many litres are the smallest and largest Mühlen safes?
According to the product pages, in the list in this article the smallest is 5 litres (Fire Bag YG75) and the largest is 390 litres (MR 171A).
Related Content
- How to Choose a Home Safe
- How to Choose a Money Safe
- Business Safes by Sector
- Steel Safe Guide
- Steel Safes · Installed Steel Safes · Fire-Resistant Steel Safe
To determine the right size for your needs, get in touch with us.