US Flag Calculator
Calculate American flag dimensions, proportions, and measurements for any size.
Enter the flag width and number of stars to calculate all official US flag dimensions including union, stripes, and star measurements.
US Flag Calculator
Calculate American flag dimensions, proportions, and measurements for any size.
Examples
Click any button below to load a standard flag size scenario.
| Flag Width & Stars | Key Dimensions | Use Case |
|---|---|---|
| Width: 60 in, Stars: 50 | Height: 31.58 in · Union: 24.0 × 17.0 in · Stripe: 2.43 in | Standard residential 3×5 ft flag |
| Width: 96 in, Stars: 50 | Height: 50.53 in · Union: 38.4 × 27.2 in · Stripe: 3.89 in | Large commercial 5×8 ft flag |
| Width: 48 in, Stars: 48 | Height: 25.26 in · Union: 19.2 × 13.6 in · Stripe: 1.94 in | Historical 48-star flag (1912–1959) |
| Width: 12 in, Stars: 50 | Height: 6.32 in · Union: 4.8 × 3.4 in · Stripe: 0.49 in | Small 12×18 in desktop flag |
About the US Flag Calculator
The US Flag Calculator computes precise dimensions for all components of the American flag based on official federal specifications. Whether you are a flag maker, a teacher creating educational materials, a historical reenactor, or a designer working on patriotic projects, accurate flag proportions are essential for producing a respectful and legally compliant flag.
The proportions of the United States flag are governed by Executive Order 10834, signed by President Eisenhower in 1959 following the admission of Hawaii as the 50th state. This executive order codified the exact mathematical relationships between all flag components. The flag's overall aspect ratio is 1.9:1 — that is, the width (fly) is always 1.9 times the height (hoist). This specific ratio was chosen to balance visual harmony with practical visibility from a distance.
The union — the blue rectangular canton in the upper left corner containing the stars — has its dimensions specified relative to the hoist (height) of the flag. The union fly (horizontal width) equals 0.76 times the flag hoist, and the union hoist (vertical height) equals 7/13 of the flag hoist. The seven-thirteenths ratio reflects the fact that the union spans the top seven of the flag's thirteen stripes. The thirteen stripes (seven red and six white, alternating with red at top and bottom) each have equal width, calculated as the total flag hoist divided by thirteen.
Star sizing follows precise rules as well. Each star's outer diameter equals 0.0616 times the flag hoist. For the current 50-star design, the stars are arranged in nine alternating rows — six rows of five stars and five rows of four stars — creating the familiar staggered grid pattern first used in 1960.
Historical flags used different star arrangements as new states joined the Union. The 48-star flag (1912–1959) arranged stars in six rows of eight. The original 13-star Betsy Ross flag placed stars in a circle. This calculator outputs dimensions for any star count, making it useful for historical reproductions and educational displays covering all eras of American history.
How to Use This Calculator
- Choose your preferred unit of measurement (Inches, Feet, Centimeters, or Meters).
- Enter the flag width — for standard residential flags this is 60 inches (5 feet); for commercial use it is typically 96 inches (8 feet).
- Enter the number of stars — use 50 for the current US flag, 48 for pre-1959 flags, or any other count for historical reproductions.
- Click 'Calculate' to see the complete set of official dimensions including height, union size, stripe width, and star diameter.
- Apply the results to your materials, adding seam allowances as needed for fabric construction.
Frequently Asked Questions
What is the official aspect ratio of the US flag?
The US flag has an official aspect ratio of 1.9:1, meaning the width (fly) is 1.9 times the height (hoist). This ratio is specified in Executive Order 10834 and must be maintained for officially compliant flags used at government buildings, schools, and other official venues.
What are the proportions of the union (blue field)?
Per Executive Order 10834, the union dimensions are expressed as fractions of the flag hoist (height). The union fly (horizontal width) equals 0.76 times the hoist, and the union hoist (vertical height) equals 7/13 of the hoist. The 7/13 ratio reflects that the union covers the top seven of the thirteen stripes. Both proportions scale with the flag's overall size.
How are the 13 stripes measured?
The 13 stripes are equal in width, and each stripe's width is simply the total flag height divided by 13. They alternate red and white, with red stripes at the top and bottom of the flag. The seven red stripes and six white stripes represent the original thirteen colonies.
How is star size calculated?
Each star's outer diameter equals one-tenth of the union height, or equivalently 0.0616 times the flag height. For the current 50-star flag, stars are arranged in a staggered 9-row grid (alternating rows of 5 and 4 stars) to evenly fill the union field.
What colors are officially specified for the US flag?
The official colors are Old Glory Red (PMS 193 C), Old Glory Blue (PMS 282 C), and white. These standardized colors ensure consistency across flags produced by different manufacturers. Using the wrong shade of red or blue can make a flag look off-color and is non-compliant for official use.
Can I make a flag in any size as long as I keep the ratio?
For personal, artistic, and educational use, you may create flags in any size while maintaining the 1.9:1 ratio and correct proportions. For official government or military use, specific sizes are prescribed by regulation. Always check applicable federal and local regulations if you plan to display a flag in an official capacity.