⚡ Free Tool · AHA + OSHA Data · No Email Required
How Many AEDs Does My Building Need?
AED Quantity Calculator
- 📋 Based on AHA 3-Min Standard
- 🏢 8 Building Types
- ⚖️ Compliance + Survival Counts
- 🆓 Free — No Signup
350K
US SCA deaths per year
Source: CDC
70%
Survival — AED within 3 min
Source: AHA
<5%
Survival — AED after 15 min
Source: NEJM
43+
US SCA deaths per year
Source: State laws 2025
🧮 Interactive Tool
Calculate Your Building's AED Coverage
Enter your building type, square footage, and number of floors. The calculator applies the AHA 3-minute drop-to-shock standard and gives you two numbers — your legal compliance minimum and the AHA survival-standard recommendation.
⚖️
⏱️ The Science
Why Placement Matters More Than Ownership
| Time to Defibrillation | Survival Rate | Real-World Scenario |
|---|---|---|
| Within 3 minutes | ~70% | AED on-site, accessible — best case |
| 8 minutes | ~20% | Average US urban EMS response time |
| 15 minutes | <5% | Rural EMS — without on-site AED |
| Each additional minute | −7% to −10% | Per AHA and NEJM clinical data |
📋
The AHA placement standard: any point in your building must be within a 3-minute drop-to-shock round trip. A responder runs to the AED, runs back, opens it, places the pads, and delivers a shock — all inside 180 seconds. This is why square footage alone isn’t enough. A 40,000 sq ft open warehouse and a 40,000 sq ft 4-story office with locked badge doors need very different AED counts.
🔢 Methodology
How AED Quantity Planning Works
1
Your 3-minute budget
Out of 180 total seconds, ~60 seconds is needed to open, place pads, analyze, and shock. That leaves 120 seconds of walking time — round-trip.
2
One-way walking time
120 seconds ÷ 2 =60 seconds to reach the AED from the farthest point in the building.
3
Distance in 60 seconds
FHWA standard walking speed: 4.4 ft/sec. In 60 seconds, an adult covers 264 feet in a straight line.
4
Real buildings have walls
A warehouse aisle is nearly straight. An office maze is not. A path factor shortens effective distance based on your layout type.
5
Coverage area
Coverage area = π × radius². This gives the maximum sq ft one AED can serve within 3 minutes.
6
Safety margin applied
Divided by 1.85 for locked doors, cabinet delays, and stress. Matches best practice from Avive and AED Total Solution.
🏢 Reference Data
Sq Ft per AED by Building Type
| Building Type | Sq Ft per AED | Why |
|---|---|---|
| Open Warehouse / Factory Floor | ~80,000 | Straight aisles, few obstructions |
| Retail / Open Showroom | ~50,000 | Some fixtures, mostly open |
| Office — Open Plan | ~40,000 | Cubicles + corridors |
| Office — Partitioned | ~30,000 | Doors, hallways, dead ends |
| Hotel / Hospitality | ~25,000 | Long corridors, locked rooms |
| School / Campus | ~22,000 | Slower walking population, wings |
| Gym / Fitness Facility | ~20,000 | High SCA risk during exercise — tighter required |
| Hospital / Clinical / Lab | ~18,000 | Wings, security doors, critical patient proximity |
🏋️
📐 Real-World Examples
Real-World Coverage Examples
🏭 1,250 sq ft Warehouse
Open layout, single floor. ~1.5% of one AED's coverage capacity. Mount centrally, unlocked, with clear signage.
✅ 1 AED Required
🏢 75,000 sq ft 2-Story Office
75,000 ÷ 40,000 = 1.88 → 2 AEDs. 2 floors × minimum 1 per floor = 2 AEDs. One centrally located on each floor.
✅ 2 AEDs Required
🏫 60,000 sq ft 2-Story School
60,000 ÷ 22,000 = 2.7 → round up + floor minimum. One per floor + coverage for larger floor's outer reach.
✅ 3 AEDs Required
🏋️ 8,000 sq ft Gym
8,000 ÷ 20,000 = 0.4 → minimum 1. High SCA risk — must be on the gym floor, not in an office.
✅ 1 AED — Floor Mounted
➕
📝 What the Calculator Needs
Quick Mode vs Advanced Mode
Quick Mode
3 fields · 30 seconds
- Total square footage
- Number of floors — each floor needs ≥1 AED; stairs destroy the 3-min budget
- Building type — sets sq-ft-per-AED automatically
Advanced Mode
Enterprise planning
- Longest distance between any two points
- Locked or badge-controlled zones
- High-risk areas (gym, pool, kitchen, machinery)
- Occupant profile (general, elderly, school-age)
- Operating hours (9-5, extended, 24/7)
- Existing AEDs already installed
Output 1: Bare Minimum
What most state laws accept for legal compliance. Keeps you from being cited — not from losing someone.
⭐ Output 2: AHA 3-Min Standard
What actually meets the survival benchmark. The difference between ~20% and ~70% survival.
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❓ Frequently Asked Questions
AED Quantity — Common Questions
A 50,000 sq ft open-plan office needs 2 AEDs — one per ~25,000 sq ft zone, centrally located — to meet the AHA 3-minute standard. The bare minimum for legal compliance is 1, but that only meets the compliance floor, not the survival standard.
Use 22,000 sq ft per AED plus 1 per floor minimum. A 60,000 sq ft 2-story school needs 3 AEDs — one per floor plus one to cover the largest floor’s outer reach. 43+ states mandate AEDs in all K-12 schools.
Use 20,000 sq ft per AED. Cardiac arrest is far more likely during exercise — even small gyms under 5,000 sq ft should have at least 1 AED on the gym floor, not locked in an office. 32 states mandate AEDs in fitness facilities.
Open warehouses cover up to 80,000 sq ft per AED due to straight aisles and few obstructions. A 1,250 sq ft warehouse needs 1. A 100,000 sq ft warehouse needs 2. Add 1 per separately fenced or badge-controlled zone.
No. Stairs and elevators add 60–90 seconds to response time, blowing the 3-minute budget entirely. Plan for at least 1 AED per occupied floor regardless of floor size.
OSHA does not specifically mandate AEDs in all workplaces but references the AHA 3-minute standard under the General Duty Clause and expects employers to be prepared for cardiac emergencies. Many state laws impose specific mandates by industry type and building size.
Centrally located on a main corridor, at adult chest height (~48 inches), in an unlocked alarmed cabinet with clear signage visible from 50+ feet. Avoid back offices, supply closets, or any location requiring a key or badge to access.
Minimum is the legal compliance floor — often just 1 device, whatever state law requires. Recommended is what the AHA 3-minute drop-to-shock standard actually requires for maximum survival probability. The gap equates to roughly the difference between 20% and 70% survival.
Monthly visual check — verify the status indicator light, confirm pad and battery expiry dates. Plus an annual deeper inspection. Most modern AEDs run daily automated self-tests and alert you if any issue is detected.
Requirements vary by state and building type. 43+ states mandate AEDs in K-12 schools. Many states require them in fitness facilities, government buildings, airports, and large public venues. Check our AED Laws by State guide for your specific situation.
📚 Citations & Sources
Data Sources
- American Heart Association — Drop-to-Shock 3-Minute Standard
- OSHA Publication 3185 — Saving Sudden Cardiac Arrest Victims in the Workplace
- New England Journal of Medicine — Delayed Time to Defibrillation after In-Hospital Cardiac Arrest
- Federal Highway Administration — Pedestrian Walking Speed Standard (4.4 ft/s)
- CDC — Sudden Cardiac Arrest Annual Mortality Data
- NIH — Cardiac Arrest Risk During Vigorous Exercise (56× baseline)
- Avive AED — Importance of Time to Defibrillation
- AED Total Solution — AED Placement Guidelines 2026
- Stryker — AED Placement Strategies for K-12 Schools
⚠️ Disclaimer
The AED Calculator and the information on this page are provided for general guidance and educational purposes only. Results are estimates based on publicly available data from the AHA, OSHA, FHWA, and peer-reviewed clinical literature. They are not medical advice, legal advice, regulatory compliance certification, or a guarantee of survival.
Every building is unique. Final AED quantity, placement, and program management should be determined in consultation with qualified professionals — including a licensed medical director, AHA-certified instructor, local EMS authority, fire marshal, and legal counsel familiar with AED laws in your jurisdiction.
AED requirements vary by jurisdiction and building type. Users are solely responsible for verifying and complying with all applicable laws. AED Brand Review disclaims all liability for any loss, injury, or damage arising from reliance on this calculator. By using this calculator you agree to our Terms of Use and Privacy Policy.