アスペクト比計算機

対角インチ、幅、高さを入力するだけで、画面の全寸法を瞬時に計算します。

1. Select Aspect Ratio

Decimal:1.78:1
Custom Ratio:
:

2. Enter Any Dimension

Diagonal, Width, or Height

Popular sizes:

Interactive Diagonal Slider27.0"
5" (Phone)27" (Desk)55" (Living Room)100"+ (Cinema)
Optional: Calculate Pixel Density (PPI) & Megapixels▼

Calculated Dimensions

Diagonal27.00″
68.58 cm
Width23.53″
59.77 cm
Height13.24″
33.62 cm
Screen Area311.5 sq in
2,009.6 cm²
Aspect Ratio Decimal1.778 : 1 (16:9)
Viewing Distance (SMPTE / THX)3.7 ft / 2.8 ft
Pixel Density & MegapixelsEnter resolution above

Interactive Visualizer

27.0″ (68.6 cm)W: 23.5″ (59.8 cm)H: 13.2″ (33.6 cm)
Letterbox / Pillarbox Simulator

Simulate black bars when watching different video ratios on this display:

Standard Displays Quick Guide

16:9 Standard
DiagonalWidth (in / cm)Height (in / cm)Area
24″20.9″ (53.1 cm)11.8″ (29.9 cm)246 sq in
27″23.5″ (59.8 cm)13.2″ (33.6 cm)312 sq in
32″27.9″ (70.8 cm)15.7″ (39.8 cm)438 sq in
55″47.9″ (121.8 cm)27.0″ (68.5 cm)1,293 sq in
65″56.7″ (143.9 cm)31.9″ (80.9 cm)1,805 sq in
100″87.2″ (221.4 cm)49.0″ (124.5 cm)4,272 sq in
Mathematical Formulas & Step-by-Step Derivation▼

Screen dimensions are calculated using the Pythagorean Theorem (W² + H² = D²) combined with the ratio proportion W / H = Rw / Rh:

1. Screen Width from Diagonal (d) and Ratio (w:h):

Width = d × w ÷ √(w² + h²)

2. Screen Height from Diagonal (d) and Ratio (w:h):

Height = d × h ÷ √(w² + h²)

3. Screen Area:

Area = Width × Height

4. Pixel Density (PPI):

PPI = √(Horiz_px² + Vert_px²) ÷ Diagonal_in

Optimal Viewing Distance: SMPTE recommends a 30-degree field of view for mixed multimedia (Distance ≈ Diagonal × 1.62), while THX recommends a 40-degree field of view for cinematic immersion (Distance ≈ Diagonal × 1.2).

FAQ

画面のアスペクト比はどのように計算しますか？

水平解像度を垂直解像度で割り、最大公約数で約分します。例：1920×1080は16:9となります。

使っている画面は16:9か16:10か確認するには？

OSのディスプレイ設定で解像度を確認します。横÷縦が約1.78なら16:9、1.6なら16:10です。