Photo Aspect Ratio Calculator
Calculate the perfect crop dimensions for any photo print size, social media platform, or display format. Enter your photo's pixel dimensions to see its native ratio, then find exact crop coordinates for standard print sizes, Instagram, Facebook, Pinterest, and any custom target ratio.
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What is Photo Aspect Ratio?
Every photograph has a native aspect ratio determined by the camera sensor that captured it. DSLR cameras shoot in 3:2 (6000×4000), smartphones in 4:3 (4032×3024), and medium format cameras in 4:3 or 3:2. When printing, publishing online, or displaying on screens with different ratios, photographers must crop strategically to fit the target format without losing important visual elements.
Understanding photo aspect ratios prevents the two most common problems in photography: unwanted cropping at the print lab (cutting off heads or critical composition elements) and image distortion when forced into social media containers. This calculator bridges the gap between your camera's native ratio and every output format you need, ensuring your images look exactly as intended everywhere they appear.
적용 수학 공식 및 방정식
이 Photo Aspect Ratio Calculator는 5가지 핵심 수학 공식을 사용합니다:
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.
Explore all calculation options on the 비율 계산기 home page.
비율 계산기 사용법
이 비율 계산기는 아래의 3단계로 쉽게 사용할 수 있습니다:
수치 입력하기
입력 칸에 알고 있는 비율 값을 입력합니다. 구하려는 미지수 자리의 칸 하나는 비워둡니다.
모드 선택하기
비율 모드(풀기, 간소화, 스케일링)를 선택합니다. 각 모드는 입력한 수치에 맞춰 다른 공식들을 적용합니다.
결과 확인하기
계산하기 버튼을 누릅니다. 결과 화면에 정답과 함께 시각적인 비율 바, 원형 차트, 상세한 단계별 풀이 과정이 출력됩니다.
실제 예제 문제 및 단계별 풀이
비율 계산기를 활용하여 아래 3가지 예제 문제를 단계별로 해결하는 과정입니다:
입력 1 Crop a 3:2 photo for an 8×10 (5:4) frame
입력 2 Calculate DPI for a 5×7 print from a 4200×3000 image
입력 3 Find the crop for Instagram 4:5 from a 4:3 photo
자주 묻는 질문 (FAQ)
What aspect ratio do DSLR cameras shoot in? ▼
Most DSLR cameras (Canon, Nikon, Sony full-frame and APS-C) shoot in 3:2 aspect ratio. Common resolutions include 6000×4000, 6720×4480, and 8640×5760. Micro Four Thirds cameras (Olympus, Panasonic) shoot in 4:3 at resolutions like 5184×3888.
What is the aspect ratio of a 4×6 print? ▼
A 4×6 print has a 3:2 aspect ratio (6÷2=3, 4÷2=2), which matches standard DSLR sensors perfectly. This means DSLR images print at 4×6 without any cropping. At 300 DPI, you need at least 1200×1800 pixels.
How much cropping occurs when printing an 8×10 from a 3:2 image? ▼
An 8×10 print uses a 4:5 ratio (wider than 3:2 in the narrow dimension). A 6000×4000 (3:2) image cropped to 4:5 becomes 5000×4000, losing 500 pixels (8.3%) from each side. Important subjects near the edges may be cropped out.
What ratio is best for Instagram photos? ▼
Instagram supports 1:1 (square, 1080×1080), 4:5 (portrait, 1080×1350), and 1.91:1 (landscape, 1080×566). The 4:5 portrait ratio typically performs best because it takes up the most screen space in the feed, increasing visibility and engagement.
How do smartphone cameras compare to DSLR aspect ratios? ▼
Most smartphones shoot in 4:3 by default (e.g., 4032×3024 on iPhone). Some offer 16:9 mode, which crops the sensor. DSLR sensors are 3:2, which is slightly wider. When printing smartphone photos at 4×6 (3:2), slight cropping is needed.
What is the best aspect ratio for a photo portfolio website? ▼
For consistent gallery presentation, standardize on one ratio per gallery section. Landscape galleries work well at 3:2 (matches most DSLR output). Portrait galleries at 2:3 or 4:5. Mixed galleries can use 4:3 as a middle ground. Consistency matters more than the specific ratio chosen.
How do I calculate print size from pixel dimensions? ▼
Divide pixel dimensions by the print DPI (typically 300 for photo quality). A 6000×4000 image at 300 DPI prints at 20×13.3 inches maximum. At 150 DPI (acceptable for viewing distance above 2 feet), it prints at 40×26.7 inches.
What aspect ratio should I use for framing photos? ▼
Standard frame sizes use these ratios: 4×6 = 3:2, 5×7 = 5:7, 8×10 = 4:5, 8.5×11 = 17:22, 11×14 = 11:14, 16×20 = 4:5. Mat boards can adapt images to different frame sizes, but the image itself must be cropped to match the mat opening ratio.
Can I change a photo's aspect ratio without cropping? ▼
Technically, only by adding canvas (white/black borders, blurred extensions, or AI-generated fill). This changes the image dimensions without removing content. Adobe Photoshop's Generative Fill and Content-Aware Fill can extend edges intelligently. Pure resizing without cropping or extension will distort the image.
What ratio does a 35mm film negative use? ▼
35mm film has a 3:2 aspect ratio (36mm × 24mm). This is why DSLR sensors — designed after 35mm film — also use 3:2. The 4×6 print size was established to match 35mm film proportions without cropping.
How do I choose between portrait and landscape for a print? ▼
Match the orientation to the subject: landscapes, cityscapes, and group photos typically work best in landscape (horizontal). Portraits, full-body shots, and tall architecture work best in portrait (vertical). Some compositions work in both — crop each to evaluate before committing.