• FDA-approved via PMA
  • Independent of manufacturers
  • Editorial · Updated July 2026
  • No manufacturer sponsorships
Get CPR + AED trained →
Sudden cardiac arrest takes ~350,000 American lives each year. Survival can exceed 70% when a shock is delivered within 3 minutes. Get CPR + AED trained →
Shop AEDs
Key takeaways
  • •Coverage is about response time, not floor area: the goal is a shock within about three minutes of collapse, which drives how many units you need and where they go.
  • •Plan by walking distance and layout: multi-floor or spread-out sites usually need more than one AED.
  • •These are planning estimates, not a legal minimum: check your AED laws by state for any mandate.
Home
›
AED Quantity Calculator
  • Free Tool · AHA + OSHA Data · No Signup

How many AEDs does your building need?

“How many AEDs do I need” is not a guess. Three inputs, 30 seconds, a planning estimate aligned to the AHA 3-minute collapse-to-shock target that you can take to procurement, finance, and your medical director, then validate with a timed walking drill.
  • Updated · July 2026
350K+
US cardiac arrests / yr

EMS-assessed OHCA · AHA

~70%

Survival · AED < 3 min

American Heart Association

7-10%

Survival lost / minute

AHA time-to-defib data

50

State laws tracked

AEDBB law tracker

AED Quantity Calculator
Based on AHA placement guidelines — 3 min response time standard

Pick your building type, square footage, and floors — the AHA-standard count calculates instantly.

Browse AED Models → Need Fleet Mgmt?
  • Quick answer · The 30-second rule

Most facilities need at least one AED. The moment a building adds a second floor, a detached structure, a high-risk zone, or a floorplate beyond roughly 22,000 square feet, a single unit cannot reach every corner inside the AHA 3-minute survival window.[1]

  • 1 AED per facility (baseline)
  • +1 per additional occupied floor
  • +1 per detached building
  • +1 per high-risk zone (gym, pool, machinery, child area)
  • +1 per every ~22,000 sq ft of indoor coverage (planning estimate; validate by timed drill)
  • Coverage planning ranges

How much area can one AED cover?

Planning ranges used across published enterprise AED deployments (labeled estimates, not a formula: the AHA publishes no square-feet-per-AED standard). Every final count gets validated with a timed walking drill against the 3-minute target.[1]
Building typePlanning range per AEDWhy
Open warehouse / factory~30,000 sq ftStraight aisles, few obstructions; machinery zones add risk-weighted units
Restaurant / retail~25,000 sq ftOpen layouts, moderate fixtures
Church / worship~25,000 sq ftLong corridors, locked rooms; balcony seating adds a unit over ~500 seats
Office / corporate~22,000 sq ftCubicles, corridors, conference rooms
School / daycare~20,000 sq ftMulti-wing layouts, slower mixed-age population
Hotel / hospitality~18,000 sq ftLong corridors, elevators, locked guest rooms
Healthcare / clinic~15,000 sq ftVulnerable population, wings, security doors
Gym / fitness~10,000 sq ftSCA risk up to ~17x during exertion[5]; tightest coverage of any facility
Ranges are planning estimates across published enterprise deployments; your building’s doors, stairs, and sightlines move the number. The drill is the standard, the table is the starting point.
  • Worked examples

What the estimate looks like in real buildings.

Warehouse · 5,000 sq ft · 1 floor

1 AED

5,000 ÷ 30,000 rounds up to one. Mount centrally on the production floor, unlocked, signage visible from both aisle ends.

Office · 50,000 sq ft · open plan

3 AEDs

50,000 ÷ 22,000 rounds up to three: reception, each elevator bank, largest open area. Badge doors push the count up; drill to confirm.

School · 60,000 sq ft · 2 stories

4 AEDs

Coverage by wing plus dedicated units for the gym and cafeteria. Detached athletic fields take a fifth. Check your state on the law tracker.

Gym · 8,000 sq ft · cardio + weights

2 AEDs (3 with pool)

Risk-weighted: one in cardio, one at free weights, and the pool deck always takes its own unit.[5]
Know how many? · Price the program · FDA PMA

You know how many AEDs. Now price the program.

Unit count is step one. Next, model the 5-year cost per device including pads and batteries, then match each location to an FDA-approved (PMA) pick. Multi-site programs route to a fleet quote.

FDA PMA approved5-year cost modelPads + batteriesFleet options
Guidance by industry

Placement quick-reference for the six most common facilities.

K-12 · mandated in most states

Schools

Main office, gym, cafeteria, athletic fields, detached buildings. Athletic zones carry the highest risk; check your state on the tracker.
School Guide →

One per floor

Offices

One per floor plus elevator banks; floorplates over ~22,000 sq ft need their own coverage.
Office Guide →

Tightest coverage

Gyms

Front desk, workout floor, cardio zone, pool deck. Exertion raises SCA risk up to ~17x.[5]
Gym Guide →

Balcony over 500 seats

Churches

Sanctuary or narthex, fellowship hall, children’s wing.
Church Guide →

One per guest floor

Hotels

Lobby, fitness center, pool deck, one per guest floor near the elevator; one per tower.
Hotel Guide →

90-second work cells

Warehouses

Shipping/receiving, break area, forklift and machinery zones; every work cell within about 90 seconds one way.
Manufacturing guide →
  • Placement strategy

Where should the first AED go?

The first AED goes where staff are always present. The second covers the highest risk. The third covers the largest unguarded space. The sequence holds across every facility type in our editorial methodology.
  • 1 · Main entrance or front desk. Permanent staffing, fastest line of sight, often the only 24/7-supervised spot.
  • 2 · Highest-risk zone. Gym, pool deck, production floor, sanctuary, child area. Risk-weighted beats square-footage-weighted.
  • 3 · Largest unguarded space. Highest occupancy, longest walk from the first two units.
  • 4 · Each detached building. Walking outside between structures burns the 3-minute budget instantly.
  • 5 · Each additional floor. Stair or elevator transit is 60 to 90 seconds each way; one per occupied floor.
Mounting: unlocked cabinet at adult chest height (~48 in), signage visible from 50+ feet, paired with a CPR pocket mask. Never behind a key or badge. Keep pads and batteries in date with monthly checks.
  • The science · time = survival

Why placement matters more than ownership.

Survival from sudden cardiac arrest is time-dependent: every minute without defibrillation cuts survival by 7 to 10 percentage points.[1] A facility can own an AED and still lose someone if retrieval takes longer than three minutes round-trip.

01

The 3-minute window

Any collapse point must be within a 3-minute drop-to-shock round trip: run to the AED, run back, place pads, deliver a shock, all inside about 180 seconds.[1]

02

Square footage alone fails

A 40,000 sq ft open warehouse and a 40,000 sq ft four-story office with badge doors need different counts. Layout, doors, and obstructions compress the reachable radius, which is why drills beat formulas.

03

Walking-speed baseline

The FHWA pedestrian standard is 4.4 ft/sec; stair transit adds 60 to 90 seconds.[3] That bounds how far one unit can actually cover.

04

OSHA guidance

OSHA Publication 3185 endorses workplace AED programs and 29 CFR 1910.151 requires medical readiness, but neither sets counts.[4] Planning estimates plus timed drills fill that gap.
  • Compliance vs coverage

Why the survival target beats the compliance floor.

Many states mandate AEDs in specific facilities: K-12 schools and fitness centers most commonly. Statute language and counts vary by state, so verify yours on the 50-state AED law tracker before procurement.

Compliance keeps you from being cited. The AHA 3-minute target is what moves survival: roughly 70 percent when the shock lands inside 3 minutes versus about 20 percent at typical EMS response times.[1] Plan to the survival target, then confirm the statute box is ticked.

Got the count · now pick + budget

Coverage is step one. Model and budget are steps two and three.

The number says how many. It does not say which AED fits your facility, or what 5 years of ownership costs.

Step 1

Find Your Perfect AED

60-second quiz, 4 questions, one personalized pick plus an alternate from FDA-approved models. No email required.

Run the 60-second quiz →

Step 2

AED Cost Calculator

True 5-year and 10-year ownership cost: device, pads, batteries, cabinet.

Run the Cost Calculator →

Deep dive

Buyer's Guide + Brands

Long-form guidance plus every brand we review: Philips, ZOLL, LIFEPAK, HeartSine, Cardiac Science, Defibtech.

Open the Buyer's Guide →
Match the Right AED Next →
Browse All 6 AED Brands
  • Common questions

Frequently asked questions.

At least one per facility, plus one per additional floor, one per detached building, one per high-risk zone, and more units as floorplates pass roughly 22,000 sq ft. Treat every output as a planning estimate and validate with a timed walking drill.

The AHA program target: collapse to first shock in about 3 minutes, covering the run to the AED, the run back, pad placement, and the shock.[1] Survival falls 7 to 10 percent per minute of delay.

Program shorthand: keep one-way retrieval to roughly 90 seconds of brisk walking so the full round trip stays inside the 3-minute window. It is the same target expressed one way instead of round trip.

Plan three: 50,000 ÷ ~22,000 rounds up. Reception, elevator banks, largest open area, then drill to confirm; badge doors and corridors move the number.

A 60,000 sq ft two-story school typically plans four: per-wing coverage plus the gym and cafeteria, and a fifth for detached fields. Verify your state mandate on the tracker and see the schools guide.

The tightest planning range of any facility, about one per 10,000 sq ft: exertion raises SCA risk up to ~17x.[5] An 8,000 sq ft gym plans two on the floor; a pool deck always takes its own.

Plan one per occupied floor. Stairs or elevators consume 60 to 90 seconds each way, which alone breaks the 3-minute round trip.

No universal mandate. 29 CFR 1910.151 requires medical readiness and OSHA Publication 3185 endorses AED programs.[4] State laws add facility-specific mandates; check the tracker.

Unlocked cabinet, ~48 inches high, signage visible from 50+ feet, never behind a key or badge. First at a staffed entrance, second in the highest-risk zone.

Monthly visual checks of the readiness light and pad/battery dates plus the manufacturer’s annual routine; modern units self-test daily. Plan replacements with pads explained and batteries explained.

  • Methodology and sources

Every calculation traces to a primary source.

  1. American Heart Association: 3-minute collapse-to-shock program target; survival decline of 7 to 10 percent per minute of delay.
  2. AHA Heart Disease and Stroke Statistics: more than 350,000 EMS-assessed out-of-hospital cardiac arrests per year, US.
  3. FHWA: pedestrian walking-speed standard of 4.4 ft/sec used in coverage timing.
  4. OSHA 29 CFR 1910.151 and OSHA Publication 3185: workplace medical readiness and AED program endorsement.
  5. Albert CM et al., NEJM 2000: SCA risk up to ~17x during vigorous exertion in habitually inactive individuals.
  6. American Red Cross: AED program and training guidance.
  7. FDA Premarket Approval (PMA) database: approval status for every model referenced by our tools.
Updated · July 2026MethodologyMedical Advisory BoardAbout AED Best Brands
Scroll to Top