Lock Grade Selection Calculator

This calculator recommends an ANSI/BHMA hardware grade (Grade 1, 2, or 3) for a door opening by scoring six factors and comparing the total against grade thresholds — the grade itself comes from ANSI/BHMA A156.2, BHMA's own published standard for bored and preassembled locks, which defines Grade 1 as the toughest cycle-tested tier and Grade 3 as the lightest-duty residential tier. Traffic level, security need, and building type each add points on their own scale, exterior doors add a flat bump (they see more abuse and weather exposure than interior doors), ADA-required openings add a small bump for accessible hardware requirements, and fire-rated doors add the largest single bump because fire doors need specific UL-listed, self-closing hardware regardless of how light the traffic is. A score of 12 or higher recommends Grade 1 (rated for 800,000+ open/close cycles), 5 or higher recommends Grade 2 (400,000+), and anything below that falls to Grade 3 (200,000+, standard residential hardware).

Two hard overrides sit on top of the scoring: any fire-rated door is forced to Grade 1 regardless of its score, and any institutional or high-security building type (hospitals, schools, government, financial) is also forced to Grade 1. The calculator also derives the maximum allowable opening force — 5 lbf for ADA-compliant interior doors, 8.5 lbf for exterior doors, or 15 lbf where fire code applies — and estimates per-opening cost from typical lockset and closer prices at the recommended grade, adding a flat $50 where a UL fire listing is required. The cycle-life and force numbers reflect general ANSI/BHMA and ADA guidance; always verify against your local building and fire code before finalizing a hardware spec, since jurisdictions can impose stricter requirements.