Flag Calculator — Dimensions, Area & Fabric
Enter your desired flag width and select the standard aspect ratio for the country or organisation you are making the flag for. The calculator instantly gives you the correct height, total fabric area, diagonal, and perimeter — everything you need to cut and sew a properly proportioned flag.
Unidad
Aspect ratio (width : height)
Vertical dimension — also called the hoist
- 1
Aspect factor (height ÷ width part)
2 ÷ 3 = 0,6667 - 2
Flag height (hoist)
150 × 0,6667 = 100
¿Cómo funciona esta calculadora?
Flag height = Width × (height-part / width-part of the aspect ratio). For a 3:2 flag, height = Width × 0.667. Area = Width × Height tells you how much fabric to buy. Common ratios: 2:1 (UK), 3:2 (most of Europe), 19:10 (USA), 1:1 (Switzerland).
Fórmula
How this is calculated
A flag's proportions are defined by its aspect ratio — the ratio of fly (width) to hoist (height). Most countries standardise this ratio in law or military specification. The United Kingdom's Union Flag is 2:1, many European national flags are 3:2, and the US flag's official proportion is 19:10. Square flags (1:1) are used by Switzerland, the Vatican, and a handful of other states.
Given a desired width and an aspect ratio of W:H, the height is simply Width × (H/W). The total fabric area (useful for estimating cost of material) is Width × Height. The diagonal — the distance between opposite corners — comes from the Pythagorean theorem: √(Width² + Height²). Perimeter is 2 × (Width + Height), relevant for calculating hem allowance or flag-pole rope attachment.
Practical note: when ordering flag fabric add 5–10 % to the area for seam allowance and hemming. All dimensions scale linearly — a flag twice as wide requires four times the fabric.
Preguntas frecuentes
The most common ratio is 3:2 (width:height) used by most European countries, the EU flag, and many others. The UK uses 2:1, the USA uses 19:10 (approximately 1.9:1), and some countries like Poland use 5:3. Switzerland and Vatican City use a square 1:1 ratio.
Hoist refers to the vertical dimension of the flag (height) — the side attached to the pole or hoist rope. Fly refers to the horizontal dimension (width) — the free end that billows in the wind. A "2:1" flag means the fly is twice the hoist.
Multiply the width by the height to get the raw area, then add 5–10 % for seam allowance and hemming. For example, a 150 cm × 100 cm flag (3:2 ratio) needs about 1.5 m² of fabric plus hem allowance, so order at least 1.65 m².
También conocido como
TG we-Calculate Editorial Team. (2026). Flag Calculator — Dimensions, Area & Fabric [Online calculator]. TG we-Calculate. https://we-calculate.com/es/calculator/flag-calculator
TG we-Calculate Editorial Team. "Flag Calculator — Dimensions, Area & Fabric." TG we-Calculate. 2026. https://we-calculate.com/es/calculator/flag-calculator.
TG we-Calculate Editorial Team, "Flag Calculator — Dimensions, Area & Fabric," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/es/calculator/flag-calculator
@misc{wecalculate_flag_calculator, title = {Flag Calculator — Dimensions, Area & Fabric}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/es/calculator/flag-calculator}}, year = {2026}, note = {TG we-Calculate} }
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