Flag Size Chart: Sizes, Pole Heights & Area Guide 2026

The flag size chart

Flag sizes run from 3x5 ft for a house flag to 30x50 ft for a monument. The chart below lists the standard sizes: the area in square feet, the aspect ratio (the long side divided by the short side), the recommended pole height, the 4x rule pole, and what each size is best for. The aspect ratios cluster around 1.50 and 1.67 — the two classic flag proportions. This is a size and pole guide, not a wind-load or engineering chart: it does not calculate wind load, pole strength, or foundation size.

How the pick works

The pick is the smallest size whose pole range top is strictly above your pole height, and on a boundary you size up: a flag that is slightly small for its pole looks lost, and a flag that is slightly large flies better than one that is too small. Below 15 ft is below the chart; above 120 ft is above the chart. The pick also shows the area, the aspect ratio, the recommended pole range, and the 4x rule pole — four times the flag length, the rule of thumb for a good-looking flag.

At the default — a 3x5 ft flag — the area is 15 sq ft, the aspect ratio is 1.67, the recommended pole is 15–20 ft, and the 4x rule pole is 20 ft. A 20 ft pole takes a 4x6 ft flag, and 15 sq ft is nearest to a 3x5 ft flag.

The worked example, line by line

Setup: flag size 3x5 ft, pole height 20 ft, flag area 15 sq ft.

Line 1 — the area. 3 × 5 = 15 sq ft.

Line 2 — the aspect ratio. 5 ÷ 3 = 1.67.

Line 3 — the recommended pole. The 3x5 row of the chart says 15–20 ft.

Line 4 — the 4x rule pole. 4 × 5 = 20 ft.

Line 5 — the reverse picks. A 20 ft pole takes a 4x6 ft flag — a boundary sizes up — and 15 sq ft is nearest to a 3x5 ft flag, exactly. Rounding convention: all figures are computed from unrounded values and rounded only for display — areas to whole square feet, aspect ratios to two decimals, so a figure worked out from the rounded numbers can differ slightly from the figure shown.

Reverse: pole heights pick 15 ft → 3x5 ft, 20 ft → 4x6 ft, 25 ft → 5x8 ft, 30 ft → 6x10 ft, 40 ft → 8x12 ft, 50 ft → 10x15 ft, 60 ft → 12x18 ft, 70 ft → 15x25 ft, 80 ft → 20x30 ft, 100 ft → 30x50 ft, 120 ft → 30x50 ft, 14 ft → BELOW CHART, 121 ft → ABOVE CHART. Areas pick 100 sq ft → 8x12 ft (96 sq ft), 150 sq ft → 10x15 ft (exact), 15 sq ft → 3x5 ft (exact), 1,500 sq ft → 30x50 ft (exact). Extras: a 5x8 flag is 2.67x the area of a 3x5 flag; a 10x15 flag is 10.00x; a 30x50 flag is 100.00x; a 20x30 flag is 40.00x.

Every size, checked

3x5 ft: 15 sq ft, aspect 1.67, pole 15–20 ft, 4x rule 20 ft — house flags, garden flags, porches. 4x6 ft: 24 sq ft, aspect 1.50, pole 20–25 ft, 4x rule 24 ft — house flags, small yards. 5x8 ft: 40 sq ft, aspect 1.60, pole 25–30 ft, 4x rule 32 ft — the standard residential flagpole size.

6x10 ft: 60 sq ft, aspect 1.67, pole 30–40 ft, 4x rule 40 ft — residential flagpoles, small businesses. 8x12 ft: 96 sq ft, aspect 1.50, pole 40–50 ft, 4x rule 48 ft — businesses, schools, parks. 10x15 ft: 150 sq ft, aspect 1.50, pole 50–60 ft, 4x rule 60 ft — commercial flagpoles, stadiums.

12x18 ft: 216 sq ft, aspect 1.50, pole 60–70 ft, 4x rule 72 ft — large commercial flagpoles. 15x25 ft: 375 sq ft, aspect 1.67, pole 70–80 ft, 4x rule 100 ft — large commercial flagpoles, arenas. 20x30 ft: 600 sq ft, aspect 1.50, pole 80–100 ft, 4x rule 120 ft — very large flagpoles, landmarks. 30x50 ft: 1,500 sq ft, aspect 1.67, pole 100–120 ft, 4x rule 200 ft — the largest standard flags, monuments.

Reverse — the other way round: pole heights pick 15 ft → 3x5 ft, 20 ft → 4x6 ft, 25 ft → 5x8 ft, 30 ft → 6x10 ft, 40 ft → 8x12 ft, 50 ft → 10x15 ft, 60 ft → 12x18 ft, 70 ft → 15x25 ft, 80 ft → 20x30 ft, 100 ft → 30x50 ft, 120 ft → 30x50 ft, 14 ft → BELOW CHART, 121 ft → ABOVE CHART. Areas pick 100 sq ft → 8x12 ft (96 sq ft), 150 sq ft → 10x15 ft, 15 sq ft → 3x5 ft, 1,500 sq ft → 30x50 ft.

What the chart assumes

The chart assumes the standard flag sizes above, with the pole ranges as listed. It assumes you measure the pole height from the ground to the top, and the flag size by its flying dimensions, length by width. It does not know the wind: a flag that fits the pole in calm air can be too much sail in a storm, so check the pole manufacturer’s guidance for a tall pole or a windy site. It does not score flag material, which changes how a flag flies and how long it lasts. With a 0 or negative pole height or area the calculator asks for a real number. Rounding convention: all figures are computed from unrounded values and rounded only for display — areas to whole square feet, aspect ratios to two decimals, so a figure worked out from the rounded numbers can differ slightly from the figure shown.

Output · formula · meaning

Who uses this

• The homeowner with a 20 ft pole: they learn the flag is 4x6 ft — so they know a boundary sizes up and a 3x5 would look small, and they check the 4x rule pole, 24 ft, before ordering.
• The business owner with a 50 ft pole: they learn the flag is 10x15 ft — so they know 150 sq ft of flag on a 50 ft pole is the standard commercial size, and they check the 12x18, which needs a 60 ft pole, before sizing up.
• The buyer who wants 100 square feet of flag: they learn the nearest size is 8x12 ft (96 sq ft) — so they know no standard size is exactly 100 sq ft, and they check the 10x15, which is exactly 150 sq ft, before choosing between the two.
• The buyer with a 121 ft pole: they learn they are above the chart — so they know no standard flag fits a pole that tall by this guide, and they check the pole manufacturer’s guidance instead of ordering the largest standard flag.

Accuracy & limitations

The figures are exact for the numbers you enter: the area is length times width, the aspect ratio is width divided by length, the 4x rule pole is four times the flag length, the pole pick is the smallest size whose pole range top is strictly above your pole height, and the area pick is the size whose area is nearest yours. What the chart cannot do is know your real pole: check the pole height, because a pole measured to the truck instead of the ground reads short, and check the wind, because this chart is a size and pole guide, not a wind-load or engineering chart. It assumes the standard sizes above; some manufacturers make non-standard sizes. For other standard sizes, see air filter size chart, hat size chart, and shoe size chart.