Selecting the correct flag size for a flagpole might seem challenging, but there are some easy tips you can use to get it right. The first thing to consider is whether you’ll be installing a house-mounted pole or an in-ground pole.

For in-ground poles, the fly, or length of the flag should be at least one-quarter the height of the pole. For example, the flag for a 20′ high flagpole should be at least 5′ in length. A 3’x5′ flag would be a great choice for a 20′ high pole. For both safety and aesthetic reasons, the length should be no larger than one-third of the flagpole height.

For house-mounted flagpoles, the process is a little different. Simply put, we recommend using a 2 1/2′ x 4′ flag for a 5′ pole and a 3′ x 5′ flag for poles larger than 5′.

Recommended flag size for various types of flagpoles and pole heights
Flagpole Type Flagpole Height in Feet Flag Size in Feet
house mounted 5′ 2.5×4
house mounted 6′ – 8′ 3×5
in-ground 15′ 3×5
in-ground 20′ 3×5
in-ground 25′ 4×6
in-ground 30′ 5×8
in-ground 40′ 6×10
in-ground 50′ 8×12
in-ground 60′ 10×15
in-ground 70′ 12×18
in-ground 80′ 15×25
in-ground 90′ 15×25
in-ground 100′ 15×25

If you’re creating your own flag or looking for dimensions of the various components on the flag, refer to our American Flag Calculator.