Occupant load and egress width calculator

IBC 2021 occupant load by space, exits required and egress widths checked level by level.

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	A	B	C	D	E	F	G	H	I
1	Occupant load by space (IBC 2021 Table 1004.5)
2	Example data — replace the blue input cells with your own.
3
4	Space	Level	Occupancy use (Factors tab)	Area (m²)	Area (ft²)	Basis	Factor (ft² per occupant)	Occupant load	Check
5	Entrance lobby	Level 1	Business areas (offices)	54.0	581.3	Gross	150	4	OK
6	Reception and waiting	Level 1	Business areas (offices)	30.0	322.9	Gross	150	3	OK
7	Multipurpose hall	Level 1	Assembly, unconcentrated (tables and chairs)	160.0	1,722.2	Net	15	115	OK
8	Café servery	Level 1	Assembly, unconcentrated (tables and chairs)	17.5	188.4	Net	15	13	OK
9	Commercial kitchen	Level 1	Commercial kitchen	31.5	339.1	Gross	200	2	OK
10	Workshop	Level 1	Industrial, workshop	96.0	1,033.3	Gross	100	11	OK
11	Storage	Level 1	Storage, stock and warehouse	14.0	150.7	Gross	300	1	OK
12	Classroom 101	Level 1	Classroom areas	59.5	640.5	Net	20	33	OK
13	Classroom 102	Level 1	Classroom areas	59.5	640.5	Net	20	33	OK
14	Library reading room	Level 2	Library, reading room	133.0	1,431.6	Net	50	29	OK
15	Open office	Level 2	Business areas (offices)	70.0	753.5	Gross	150	6	OK
16	Office 201 and 202	Level 2	Business areas (offices)	28.0	301.4	Gross	150	3	OK

Showing the first 16 of 24 rows and 9 of 9 columns. Cells with formulas show the formula on hover.

	A	B	C	D	E	F	G	H	I
1	Occupant load, exits and egress widths
2	Example data — replace the blue input cells with your own. Check the results with the adopted code.
3
4	Egress width factors (IBC 2021, Section 1005.3)
5	Stairways, inches per occupant	0.3
6	Other egress components, inches per occupant	0.2
7	Millimetres per inch	25.4
8
9	Exits and widths by level
10	Level	Occupant load	Exits required	Exits provided	Clear width per exit provided (mm)	Total exit width provided (mm)	Required width, other components (mm)	Required width per exit (mm)	Check
11	Level 1	215	2	3	1,100	3,300	1,092	546	OK
12	Level 2	154	2	2	1,000	2,000	782	391	OK
13	Total occupant load (all levels)	369
14	Exits required: 2 up to 500 occupants, 3 from 501 to 1000, 4 above 1000. Confirm this count and the rules for your building with the adopted code.
15
16	Stairway serving the upper level

Showing the first 16 of 27 rows and 9 of 9 columns. Cells with formulas show the formula on hover.

	A	B	C	D	E
1	Occupant load factors (IBC 2021 Table 1004.5)
2	Example data — replace the blue input cells with your own. Factors are published IBC 2021 values; confirm them against the adopted code.
3
4	Conversion
5	Square feet per square metre		10.76391		1 m² = 10.76391 ft². Factors are in square feet, as the code states them.
6
7	Occupancy use	Basis	Factor (ft² per occupant)	Factor (m² per occupant)	IBC 2021 Table 1004.5 use
8	Assembly, unconcentrated (tables and chairs)	Net	15	1.3935	Assembly: unconcentrated (tables and chairs)
9	Assembly, concentrated (chairs only)	Net	7	0.6503	Assembly: concentrated (chairs only, not fixed)
10	Assembly, standing space	Net	5	0.4645	Assembly: standing space
11	Business areas (offices)	Gross	150	13.9355	Business areas
12	Classroom areas	Net	20	1.8581	Educational: classroom areas
13	Mercantile, sales floor	Gross	60	5.5742	Mercantile: sales area on the floor
14	Storage, stock and warehouse	Gross	300	27.8709	Storage: stock, shipping areas
15	Residential (dwelling units)	Gross	200	18.5806	Residential
16	Commercial kitchen	Gross	200	18.5806	Kitchen, commercial

Showing the first 16 of 22 rows and 5 of 5 columns. Cells with formulas show the formula on hover.

	A
1	Occupant load and egress width calculator
2	Notes: what this workbook does, how to use it and the method behind it.
3
4	What it does
5	Works out the occupant load of each space from its area and the IBC 2021 Table 1004.5 factor for its use. It totals the loads by level, sets the number of exits required, and checks the exit and stairway widths you provide against the per-…
6
7	How to use it
8	1. On the Factors tab, check the occupancy list. Factors are in square feet per occupant, as the code states them.
9	2. On the Spaces tab, enter each space, its level, its occupancy use from the drop-down list and its area in square metres. Use net areas for net factors and gross areas for gross factors.
10	3. Read the occupant load of each space in column H. A check of OK means the use was found on the Factors tab.
11	4. On the Egress tab, enter the exits provided and their clear widths for each level, and the stairway width for the upper level.
12	5. Read the checks and the overall result at the foot of the Egress tab.
13
14	Formulas and method
15	Area (ft²) = area (m²) × 10.76391. Occupant load = ROUNDUP(area ÷ factor), with the division rounded to six decimals first so exact values do not round up by mistake.
16	Exits required from the total occupant load of each level: 2 up to 500, 3 from 501 to 1000, 4 above 1000.

Showing the first 16 of 33 rows and 1 of 1 columns. Cells with formulas show the formula on hover.

What does this template do?

This calculator works out the occupant load of each space from its area and the IBC 2021 Table 1004.5 factor for its use. It then sets the number of exits and checks the exit and stairway widths against the per-occupant allowances. The example is a fictional two-level community learning centre with 17 spaces.

Occupant load is the area divided by the factor, rounded up. Areas are entered in square metres and converted to square feet, because the code states its factors in square feet per occupant. Net and gross factors both appear in the Factors table, with a basis column that shows which applies.

The Egress tab totals loads by level, sets the exits required at 2, 3 or 4 for up to 500, up to 1,000 and above 1,000 occupants, and checks the exits and clear widths you provide. Stairways use 0.3 inches per occupant and other components use 0.2 inches.

Use it for early egress planning and to check your numbers against the code. It does not replace a review of travel distance, exit separation or accessibility.

What’s inside

Occupant load = ROUNDUP(area in ft² ÷ factor) using IBC 2021 Table 1004.5 factors
Thirteen occupancy factors, net or gross, with a basis column and a drop-down for each space
Exits required by level: 2 up to 500, 3 up to 1,000, 4 above 1,000 occupants
Required width: 0.2 in per occupant for other components and 0.3 in for stairways, converted to mm
Checks flag exits or widths that fall short, with an overall result

Which tabs does the workbook have?

Tab	What it holds
Spaces	Each space with level, occupancy use, area, factor, and the occupant load rounded up.
Egress	Occupant load by level, exits required and provided, widths, the stairway check and the overall result.
Factors	IBC 2021 Table 1004.5 occupancy factors in square feet and square metres, with the basis and the code use.
Notes	What the workbook does, how to use it, the formulas, the simplifications and the professional-verification note.

What formulas does this template use?

This template holds 120 formulas in 330 cells across 4 tabs, so 36% of its cells calculate. They use 10 distinct functions; the longest formula is 92 characters and 54 of them read from another tab.

Function	Uses	What it does
`IF`	84	one result when a test is true, another when false
`IFERROR`	34	swaps an error for a fallback value
`INDEX`	34	value at a position in a range
`MATCH`	34	position of a value in a range
`ROUND`	17	rounds to a number of digits
`ROUNDUP`	17	rounds away from zero
`SUM`	4	adds numbers
`AND`	2	true when every test is true
`COUNTIF`	2	counts cells meeting one condition
`SUMIF`	2	adds values meeting one condition

Counted from the workbook itself. Only functions that Excel, LibreOffice Calc, Google Sheets and Apple Numbers evaluate the same way are used, so the formulas survive every download format.

How do you use it?

On the Factors tab, confirm the occupancy list and factors against the adopted code.
On the Spaces tab, enter each space, its level, its occupancy use and its area in m².
Read the occupant load of each space and check that each shows OK.
On the Egress tab, enter the exits and clear widths provided for each level, and the stairway width.
Read the checks and the overall result at the foot of the Egress tab.

What is it good for?

Early egress planning for a new or altered building
Checking exit counts and widths during design development
Teaching how occupant load and egress width are calculated
Testing how a change of use alters the required exits

Questions about this sheet

Which factor applies to a classroom or a library?

Use Classroom areas (20 net) for teaching rooms. For libraries, use Library reading room (50 net) or Library stack area (100 gross), as the code defines them.

Why is the area converted to square feet?

IBC 2021 Table 1004.5 states its factors in square feet per occupant. The sheet converts your square metres first so the division matches the code.

Does the sheet check travel distance or exit separation?

No. Those rules depend on the plan, so they are outside this calculator. Check them with the drawings and the adopted code.

Are these results code approved?

No. They are for planning and checking. Confirm the occupant load, exits and widths with the adopted code and a qualified code consultant.