40 psf live · 10 psf dead · L/360

Floor Joists - 40 psf Live Load (Living Areas)

Living rooms, kitchens, halls and other non-sleeping floor areas. Spans are for repetitive members (three or more). Southern Pine values reflect the SPIB design values referenced by the IRC.

Source: International Residential Code (IRC), 2018 - Table R502.3.1(2) - Floor Joist Spans, 40 psf Live Load. Published by International Code Council.

Edition: These values are transcribed from the IRC 2018 tables. The ICC has since published IRC 2021 and IRC 2024, and the edition in force varies by jurisdiction - confirm the table and edition adopted by your local building department before relying on a span.

Floor Joists - 40 psf Live Load (Living Areas). Live load 40 psf, dead load 10 psf, deflection limit L/360. Spans in feet-inches; “-” means the source leaves that cell blank.
Spacing	Species & grade	2x6	2x8	2x10	2x12
12″ o.c.	Douglas Fir-Larch · SS	11′-4″	15′-0″	19′-1″	23′-3″
12″ o.c.	Douglas Fir-Larch · #1	10′-11″	14′-5″	18′-5″	22′-0″
12″ o.c.	Douglas Fir-Larch · #2	10′-9″	14′-2″	18′-0″	20′-11″
12″ o.c.	Douglas Fir-Larch · #3	8′-11″	11′-3″	13′-9″	16′-0″
12″ o.c.	Hem-Fir · SS	10′-9″	14′-2″	18′-0″	21′-11″
12″ o.c.	Hem-Fir · #1	10′-6″	13′-10″	17′-8″	21′-6″
12″ o.c.	Hem-Fir · #2	10′-0″	13′-2″	16′-10″	20′-4″
12″ o.c.	Hem-Fir · #3	8′-8″	11′-0″	13′-5″	15′-7″
12″ o.c.	Spruce-Pine-Fir · SS	10′-6″	13′-10″	17′-8″	21′-6″
12″ o.c.	Spruce-Pine-Fir · #1	10′-3″	13′-6″	17′-3″	20′-7″
12″ o.c.	Spruce-Pine-Fir · #2	10′-3″	13′-6″	17′-3″	20′-7″
12″ o.c.	Spruce-Pine-Fir · #3	8′-8″	11′-0″	13′-5″	15′-7″
12″ o.c.	Southern Pine · SS	11′-2″	14′-8″	18′-9″	22′-10″
12″ o.c.	Southern Pine · #1	10′-9″	14′-2″	18′-0″	21′-11″
12″ o.c.	Southern Pine · #2	10′-3″	13′-6″	16′-2″	19′-1″
12″ o.c.	Southern Pine · #3	8′-2″	10′-3″	12′-6″	14′-9″
16″ o.c.	Douglas Fir-Larch · SS	10′-4″	13′-7″	17′-4″	21′-1″
16″ o.c.	Douglas Fir-Larch · #1	9′-11″	13′-1″	16′-5″	19′-1″
16″ o.c.	Douglas Fir-Larch · #2	9′-9″	12′-9″	15′-7″	18′-1″
16″ o.c.	Douglas Fir-Larch · #3	7′-8″	9′-9″	11′-11″	13′-1″
16″ o.c.	Hem-Fir · SS	9′-9″	12′-10″	16′-5″	19′-11″
16″ o.c.	Hem-Fir · #1	9′-6″	12′-7″	16′-0″	18′-10″
16″ o.c.	Hem-Fir · #2	9′-1″	12′-0″	15′-2″	17′-7″
16″ o.c.	Hem-Fir · #3	7′-6″	9′-6″	11′-8″	13′-6″
16″ o.c.	Spruce-Pine-Fir · SS	9′-6″	12′-7″	16′-0″	19′-6″
16″ o.c.	Spruce-Pine-Fir · #1	9′-4″	12′-3″	15′-5″	17′-10″
16″ o.c.	Spruce-Pine-Fir · #2	9′-4″	12′-3″	15′-5″	17′-10″
16″ o.c.	Spruce-Pine-Fir · #3	7′-6″	9′-6″	11′-8″	13′-6″
16″ o.c.	Southern Pine · SS	10′-2″	13′-4″	17′-0″	20′-9″
16″ o.c.	Southern Pine · #1	9′-9″	12′-10″	16′-1″	19′-1″
16″ o.c.	Southern Pine · #2	9′-4″	11′-10″	14′-0″	16′-6″
16″ o.c.	Southern Pine · #3	7′-1″	8′-11″	10′-10″	12′-10″
19.2″ o.c.	Douglas Fir-Larch · SS	9′-8″	12′-10″	16′-4″	19′-10″
19.2″ o.c.	Douglas Fir-Larch · #1	9′-4″	12′-4″	15′-0″	17′-5″
19.2″ o.c.	Douglas Fir-Larch · #2	9′-2″	11′-8″	14′-3″	16′-6″
19.2″ o.c.	Douglas Fir-Larch · #3	7′-0″	8′-11″	10′-11″	12′-7″
19.2″ o.c.	Hem-Fir · SS	9′-2″	12′-1″	15′-5″	18′-9″
19.2″ o.c.	Hem-Fir · #1	9′-0″	11′-10″	14′-10″	17′-2″
19.2″ o.c.	Hem-Fir · #2	8′-7″	11′-3″	13′-10″	16′-1″
19.2″ o.c.	Hem-Fir · #3	6′-10″	8′-8″	10′-7″	12′-4″
19.2″ o.c.	Spruce-Pine-Fir · SS	9′-0″	11′-10″	15′-1″	18′-4″
19.2″ o.c.	Spruce-Pine-Fir · #1	8′-9″	11′-6″	14′-1″	16′-3″
19.2″ o.c.	Spruce-Pine-Fir · #2	8′-9″	11′-6″	14′-1″	16′-3″
19.2″ o.c.	Spruce-Pine-Fir · #3	6′-10″	8′-8″	10′-7″	12′-4″
19.2″ o.c.	Southern Pine · SS	9′-6″	12′-7″	16′-0″	19′-6″
19.2″ o.c.	Southern Pine · #1	9′-2″	12′-1″	14′-8″	17′-5″
19.2″ o.c.	Southern Pine · #2	8′-6″	10′-10″	12′-10″	15′-1″
19.2″ o.c.	Southern Pine · #3	6′-5″	8′-2″	9′-10″	11′-8″
24″ o.c.	Douglas Fir-Larch · SS	9′-0″	11′-11″	15′-2″	18′-5″
24″ o.c.	Douglas Fir-Larch · #1	8′-8″	11′-0″	13′-5″	15′-7″
24″ o.c.	Douglas Fir-Larch · #2	8′-3″	10′-5″	12′-9″	14′-9″
24″ o.c.	Douglas Fir-Larch · #3	6′-3″	8′-0″	9′-9″	11′-3″
24″ o.c.	Hem-Fir · SS	8′-6″	11′-3″	14′-4″	17′-5″
24″ o.c.	Hem-Fir · #1	8′-4″	10′-10″	13′-3″	15′-5″
24″ o.c.	Hem-Fir · #2	7′-11″	10′-2″	12′-5″	14′-4″
24″ o.c.	Hem-Fir · #3	6′-2″	7′-9″	9′-6″	11′-0″
24″ o.c.	Spruce-Pine-Fir · SS	8′-4″	11′-0″	14′-0″	17′-0″
24″ o.c.	Spruce-Pine-Fir · #1	8′-1″	10′-3″	12′-7″	14′-7″
24″ o.c.	Spruce-Pine-Fir · #2	8′-1″	10′-3″	12′-7″	14′-7″
24″ o.c.	Spruce-Pine-Fir · #3	6′-2″	7′-9″	9′-6″	11′-0″
24″ o.c.	Southern Pine · SS	8′-10″	11′-8″	14′-11″	18′-1″
24″ o.c.	Southern Pine · #1	8′-6″	11′-3″	13′-1″	15′-7″
24″ o.c.	Southern Pine · #2	7′-7″	9′-8″	11′-5″	13′-6″
24″ o.c.	Southern Pine · #3	5′-9″	7′-3″	8′-10″	10′-5″

Per-combination pages

Jump to a specific span

Frequently asked questions

What deflection limit do these spans assume?

L/360. The L is the span itself and the number underneath is the fraction of that span the member is allowed to bend under the table's design load, so two tables can cover the same lumber and the same load and still publish different spans purely because one allows more bend than the other.

What loading does this table use?

40 psf live load plus 10 psf dead load. That load case is what the table was published for: Living rooms, kitchens, halls and other non-sleeping floor areas.

Can I interpolate between joist spacings?

No. The source table (International Residential Code (IRC), 2018 - Table R502.3.1(2) - Floor Joist Spans, 40 psf Live Load (International Code Council).) publishes a separate span only at the listed on-center spacings, and every figure on this site is a verbatim cell from that table - nothing is computed or interpolated. If your layout falls between two published spacings, the wider spacing's shorter span is the one the table supports.