Smart lock specifications come from manufacturers worldwide using different measurement systems. Converting units accurately prevents costly ordering mistakes, ensures proper fit, and helps you compare products across regions.
💡 Key Takeaways
- ✓Precision is critical: 0.5mm error can cause installation failures in hotel locks
- ✓Measure in millimeters: More precise than fractional inches for door hardware
- ✓Understand voltage: Battery energy conversions require correct voltage (3.7V for lithium)
- ✓Verify before ordering: Use actual measurements, not nominal building specifications
Common Conversion Scenarios
Hotel operators frequently need to convert between measurement systems:
Door Dimensions
US manufacturers spec in inches, European in millimeters. Door thickness of 1.75" = 44.45mm.
Battery Capacity
Batteries rated in mAh, but energy consumption shown in Wh. Need voltage to convert accurately.
Operating Temperature
US uses Fahrenheit, rest of world uses Celsius. -4°F = -20°C minimum operating temp.
Comprehensive Conversion Reference
Essential conversions for smart lock specifications:
| Metric Unit | Value | = | Imperial Unit | Common Use |
|---|---|---|---|---|
| 1 millimeter | 1 mm | = | 0.03937 inch | Precision measurements |
| 1 centimeter | 1 cm | = | 0.3937 inch | Small dimensions |
| 1 inch | 1 in | = | 25.4 mm | Door thickness, backset |
| 1 foot | 1 ft | = | 304.8 mm | Door height/width |
| 1 meter | 1 m | = | 39.37 inches | Large measurements |
| Standard door | 44 mm | = | 1.73 inches | Most common thickness |
Rounding errors can be costly: A 1.75" door spec rounded to 44mm (should be 44.45mm) may result in locks that don't fit properly. Always use precise conversions for critical dimensions. When in doubt, measure in millimeters—it's more precise than fractions of inches.
How Unit Conversion Works
Understanding the conversion process helps prevent errors. Here's how our converter processes different unit types:
📏 Length Conversion
🔋 Energy Conversion
🌡️ Temperature Conversion
Regional Lock Standards: US vs Europe vs Asia
Smart lock specifications vary by region. Here's a comprehensive comparison to help you understand different market standards:
| Specification | United States (ANSI) | Europe (EN) | Asia/International | Notes |
|---|---|---|---|---|
| Door Thickness | 1.375" - 1.75" (35-44.5mm) | 38-45mm (1.5-1.77") | 35-50mm (1.38-1.97") | Most hotels: 44-45mm. Measure actual doors. |
| Backset | 2.375" or 2.75" (60.3 or 70mm) | 60mm or 70mm (2.36" or 2.76") | 60mm standard (2.36") | Distance from door edge to lock center. Critical for alignment. |
| Cylinder Diameter | 1.0625" (27mm) | 25mm or 30mm (0.98" or 1.18") | Varies widely (25-35mm) | Hole for keyway or cylinder. Check existing locks. |
| Cross Bore | 2.125" (54mm) | Not standard (mortise locks) | 50-55mm (1.97-2.17") | Large hole through door face. Common in US cylindrical locks. |
| Battery Type | 4× AA (alkaline) | 4× AA or CR123A (lithium common) | Rechargeable (18650 Li-ion) | Affects capacity conversions. AA: 2500mAh, CR123A: 1500mAh |
| Operating Temp | -4°F to 140°F (-20°C to 60°C) | -20°C to 60°C (-4°F to 140°F) | -10°C to 55°C (14°F to 131°F) | Indoor controlled environments. Outdoor locks wider range. |
- Mixed Property Portfolio: If you operate hotels in multiple regions, standardize on metric (millimeters) for all specifications—it's more universal and precise.
- Ordering from Different Manufacturers: Always specify the measurement system you need. Most global manufacturers can supply both ANSI and EN compatible locks.
- Retrofit Projects: Measure existing door prep in both units and verify against manufacturer specs before ordering. A 2mm difference can matter.
- Battery Logistics: Plan for regional battery availability. AA alkaline (US) vs lithium CR123A (Europe) affects your inventory management.