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Calcimator

Shelter Capacity Calculator

Calculate emergency shelter capacity from floor area, per-person space standards, and resource needs.

Inputs

%
%

Results

Max shelter capacity

58

Usable area (sq ft)3,500
Standard spots52
ADA-accessible spots6
Cots needed58
Restrooms / port-a-potties2
Daily water (gal)174
Total water (gal)522
Total meals needed522
How to Use This Calculator
  1. Enter Total Floor Area (sq ft) of the shelter facility.
  2. Set Sq Ft per Person — SPHERE standard is 3.5 m2 (37.7 sq ft) per person minimum.
  3. Enter Usable Area (%) to exclude walls, equipment, and circulation.
  4. Set ADA-Accessible % to ensure compliance with accessibility requirements.
  5. Review Max Shelter Capacity and ADA-accessible spaces to plan shelter activation.

How the result changes with Total floor area (sq ft)

Total floor area (sq ft)Max shelter capacity
100,0901,167
350,0654,084
650,0357,583
900,01010,500

What each input means

Total floor area (sq ft)
Total floor area of the building or facility.
Sq ft per person
Space per person (Red Cross min: 40, FEMA recommended: 60).
Usable area (%)
Percentage of floor area usable for sheltering after excluding hallways, kitchens, and storage.
Shelter duration (days)
Expected number of days the shelter will be operational.
ADA-accessible (%)
Percentage of spots designated as ADA-accessible.

What each result means

Max shelter capacity
Maximum number of people the facility can shelter.
Usable area (sq ft)
Actual floor area available for sheltering.
Standard spots
Number of standard sleeping spots.
ADA-accessible spots
Number of ADA-accessible sleeping spots.
Cots needed
Number of cots to acquire or deploy.
Restrooms / port-a-potties
Minimum restroom facilities needed (1 per 40 people, SPHERE standard).
Daily water (gal)
Daily water requirement at 3 gal/person (1 drinking + 2 sanitation).
Total water (gal)
Total water needed for the full shelter duration.
Total meals needed
Total meal servings for the full shelter duration (3 meals/person/day).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Total floor area (sq ft) = 5000, Sq ft per person = 60, Usable area (%) = 70, Shelter duration (days) = 3 = 5 input(s) provided
  2. Calculate Max shelter capacity
    Max shelter capacity
    58 = 58
  3. Calculate Usable area
    Usable area = totalFloorAreaSqFt * (usablePercentage / 100)
    3500 = 3500
  4. Calculate Standard spots
    Standard spots
    52 = 52

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