Photo Aspect Ratio Calculator
The Photo Aspect Ratio Calculator helps photographers match their images to standard print sizes and social media dimensions. Compare print formats like 4×6, 5×7, 8×10, and 11×14, and calculate the exact crop needed to fit each frame without distortion.
🕐 Recent Calculations
What is Photo Aspect Ratio?
Photo aspect ratio determines how a photograph fits into print frames, social media formats, and digital displays. A photo shot in 3:2 (standard DSLR) must be cropped to 5:4 to fit an 8×10 frame, losing some content at the edges. Understanding photo ratios prevents unexpected cropping.
Common photo print ratios include 3:2 (4×6 prints), 7:5 (5×7 prints), 5:4 (8×10 and 16×20 prints), and 7:5 (5×7 prints). Social media ratios differ: Instagram uses 1:1 and 4:5, Facebook covers use 205:78, and Pinterest pins use 2:3.
Formules et Équations utilisées
Ce calculateur s'appuie sur 5 équations fondamentales :
1 Print Size to Aspect Ratio ▼
An 8×10 print has a ratio of 8:10 = 4:5. A 4×6 print has a ratio of 4:6 = 2:3.
2 Crop Dimensions for Target Ratio ▼
To crop a 6000×4000 photo to 5:4: Crop Height = 6000 × (4/5) = 4800. Since 4800 > 4000, crop width instead: Crop Width = 4000 × (5/4) = 5000.
3 DPI Calculation for Print ▼
A 6000px wide image printed at 8 inches = 6000/8 = 750 DPI. For quality printing, DPI should be at least 300.
Comment utiliser ce calculateur
Pour utiliser ce Calculateur de Ratio, suivez ces 3 étapes :
Saisir les Valeurs
Saisissez les valeurs de ratio connues dans les champs. Laissez un champ vide — c'est la valeur manquante que le calculateur va chercher à résoudre.
Choisir le Mode
Sélectionnez le mode de ratio — Résoudre, Simplifier ou Mettre à l'échelle. Chaque mode applique des formules différentes à vos valeurs.
Obtenir les Résultats
Cliquez sur Calculer. L'écran de résultats affiche la réponse avec une barre de ratio interactive, un diagramme circulaire et le détail des calculs.
Exemples Pratiques et Solutions Étape par Étape
Voici 3 exemples de calculs résolus avec les étapes détaillées grâce à ce calculateur :
Saisie 1 Crop a 3:2 photo for an 8×10 (5:4) frame
Saisie 2 Calculate DPI for a 5×7 print from a 4200×3000 image
Saisie 3 Find the crop for Instagram 4:5 from a 4:3 photo
Foire Aux Questions
What aspect ratio is a 4×6 photo? ▼
A 4×6 photo has an aspect ratio of 2:3 (or 3:2 in landscape). This matches the standard 35mm camera sensor ratio, so DSLR photos fit 4×6 prints perfectly without cropping.
Why do my photos get cropped when printing 8×10? ▼
Most cameras shoot in 3:2 ratio, but 8×10 prints use 4:5 ratio. The 3:2 is wider, so the sides get cropped to fit the narrower 4:5 frame. Always review the crop preview before printing.
What is the best aspect ratio for portrait photography? ▼
4:5 is popular for portrait photography as it provides more vertical space for head-to-waist framing. It maps perfectly to 8×10 and 16×20 print sizes and is Instagram's preferred portrait format.
How do I resize photos for multiple social media platforms? ▼
Create crops at each platform's native ratio: 1:1 for Instagram feed, 4:5 for Instagram portrait, 9:16 for Stories/Reels, 16:9 for YouTube thumbnails, and 2:3 for Pinterest pins.
What resolution is needed for a large format print? ▼
For prints larger than 24 inches, 150-200 DPI is acceptable because viewers stand farther back. A 24×36 poster at 150 DPI needs 3600×5400 pixels (about 19 MP).