Screen Ratio Calculator

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Screen Ratio Calculator
Calculate Aspect Ratio (using Width & Height)Calculate Width (using Height & Ratio)Calculate Height (using Width & Ratio)
Result:
Enter values and click calculate to see the screen specs.
function updateFields(){var type=document.getElementById('calc_type').value;document.getElementById('row_w').style.display=(type==='get_ratio'||type==='get_height')?'table-row':'none';document.getElementById('row_h').style.display=(type==='get_ratio'||type==='get_width')?'table-row':'none';document.getElementById('row_rw').style.display=(type!=='get_ratio')?'table-row':'none';document.getElementById('row_rh').style.display=(type!=='get_ratio')?'table-row':'none';document.getElementById('answer').innerHTML='Enter values and click calculate to see the screen specs.';}function getGCD(a,b){return b?getGCD(b,a%b):a;}function calculateRatio(){var type=document.getElementById('calc_type').value;var w=parseFloat(document.getElementById('input_w').value);var h=parseFloat(document.getElementById('input_h').value);var rw=parseFloat(document.getElementById('input_rw').value);var rh=parseFloat(document.getElementById('input_rh').value);var steps=document.getElementById('showSteps').checked;var out=";if(type==='get_ratio'){if(isNaN(w)||isNaN(h)){alert('Please enter Width and Height');return;}var common=getGCD(w,h);var rW=w/common;var rH=h/common;var diag=Math.sqrt(Math.pow(w,2)+Math.pow(h,2));out='Aspect Ratio: '+rW+':'+rH+'
';out+='Diagonal: '+diag.toFixed(2)+'
';if(steps){out+='
Steps:
1. GCD of '+w+' and '+h+' is '+common+'
2. '+w+'/'+common+' = '+rW+'
3. '+h+'/'+common+' = '+rH+'
4. Diagonal = √('+w+'² + '+h+'²) = '+diag.toFixed(2)+'
';}}else if(type==='get_width'){if(isNaN(h)||isNaN(rw)||isNaN(rh)){alert('Please enter Height, Ratio Width, and Ratio Height');return;}var calcW=(h/rh)*rw;var diag=Math.sqrt(Math.pow(calcW,2)+Math.pow(h,2));out='Calculated Width: '+calcW.toFixed(2)+'
';out+='Diagonal: '+diag.toFixed(2)+'
';if(steps){out+='
Steps:
1. Width = (Height / Ratio Height) × Ratio Width
2. Width = ('+h+' / '+rh+') × '+rw+' = '+calcW.toFixed(2)+'
';}}else if(type==='get_height'){if(isNaN(w)||isNaN(rw)||isNaN(rh)){alert('Please enter Width, Ratio Width, and Ratio Height');return;}var calcH=(w/rw)*rh;var diag=Math.sqrt(Math.pow(w,2)+Math.pow(calcH,2));out='Calculated Height: '+calcH.toFixed(2)+'
';out+='Diagonal: '+diag.toFixed(2)+'
';if(steps){out+='
Steps:
1. Height = (Width / Ratio Width) × Ratio Height
2. Height = ('+w+' / '+rw+') × '+rh+' = '+calcH.toFixed(2)+'
';}}document.getElementById('answer').innerHTML=out;}

Calculator Use

The screen ratio calculator is a specialized tool designed for designers, photographers, and tech enthusiasts to determine the proportional relationship between the width and height of any display. Whether you are working with pixels for a website banner or inches for a physical television screen, this tool provides instant conversions and aspect ratio reductions.

This calculator supports three primary modes of operation:

Calculate Aspect Ratio
Enter the width and height to find the simplified ratio (e.g., 16:9) and the diagonal length using the Pythagorean theorem.
Calculate Missing Dimension
If you know the desired ratio and one dimension (either width or height), the calculator will determine the other dimension to maintain perfect proportions.
Show Solution Steps
Enable this option to see the mathematical breakdown, including the Greatest Common Divisor (GCD) used to reduce the ratio.

How It Works

At its core, screen ratio calculation relies on geometry and basic algebra. The aspect ratio represents the fraction of width over height, reduced to its simplest form. The formulas used in this screen ratio calculator are:

Simplified Ratio = (Width / GCD) : (Height / GCD)

Diagonal = √(Width² + Height²)

  • GCD: The Greatest Common Divisor is the largest positive integer that divides both numbers without a remainder.
  • Width/Height: These can be in pixels (px), inches (in), centimeters (cm), or any other unit of measure.
  • Diagonal: This represents the physical size of the screen from one corner to the opposite corner.

Calculation Example

Example: Suppose you have a monitor with a resolution of 2560 pixels wide and 1440 pixels high. You want to find the aspect ratio.

Step-by-step solution:

  1. Enter Width = 2560
  2. Enter Height = 1440
  3. Find the GCD of 2560 and 1440: The GCD is 160.
  4. Divide both numbers by 160: 2560 / 160 = 16; 1440 / 160 = 9.
  5. Resulting Aspect Ratio: 16:9
  6. Calculate Diagonal: √(2560² + 1440²) ≈ 2937.21 pixels.

Common Questions

What is the most common screen ratio?

Currently, 16:9 is the international standard for HDTV, most computer monitors, and gaming consoles. Older television sets and monitors typically used a 4:3 ratio, which is closer to a square shape.

How does resolution affect the ratio?

Resolution is the total number of pixels, while the ratio is the proportional shape. Two different resolutions, like 1920×1080 and 3840×2160, both share the same 16:9 aspect ratio, meaning the shape of the image is identical even if the clarity differs.

What is an Ultrawide ratio?

Ultrawide monitors usually feature a 21:9 aspect ratio. This provides more horizontal screen real estate, which is highly valued for cinematic viewing and productivity multitasking. You can use our screen ratio calculator to verify if a custom resolution fits the 21:9 standard.

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