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Resize an image to 300×400 pixels
To resize an image to 300×400 px, enter 300 × 400 px and pick crop to fill so the 3:4 frame is not stretched: a 4:3 phone photo loses 43.8% of its area (a centred 2268×3024 crop). The result has 0.12 megapixels; as a JPEG, a detailed outdoor photo is about 40.4 KB at the panel's default quality 85 (30.2 KB at quality 75).
300×400 px
JPG · no file-size limit · 300x400 px · white background
No file-size limit is set: PixelFit saves at high quality and changes only the format and any pixel size you set.
Fit, background and padding crop to fill · white background
Saving presets is part of Pro.
The result appears here: the exact byte count, pixel size and quality, the size before and after, a preview and a download button.
The batch kit (one ZIP for up to 500 photos, several photos merged into one PDF) is part of Pro.
300×400 at a glance
| Pixel size | 300×400 px (120,000 pixels) |
|---|---|
| Aspect ratio | 3:4, portrait (width ÷ height = 0.75) |
| Megapixels | 0.12 MP |
| Decoded in memory | 469 KB RGBA · 352 KB RGB |
| Sharp on screen at | 300×400 CSS px at 1×, 150×200 at 2×, 100×133 at 3× density |
| Print size at 300 DPI | 1×1.33 in (2.5×3.4 cm) |
| Estimated JPEG (outdoor photo, quality 75) | 30.2 KB |
| JPEG without a KB limit (panel default, quality 85) | 40.4 KB |
What 300×400 means in pixels
300×400 is a portrait frame, 1.33 times as tall as it is wide, 120,000 pixels in total (0.12 megapixels). Its sides reduce to 3:4 (0.75 as a decimal), so any picture cropped to 3:4 scales to it without distortion.
It is thumbnail scale: a 12 MP phone photo carries 102 times more pixels, so the resize discards most of them and the stepped downscale matters for sharpness. Shown 1:1 it fills 300×400 CSS px on a standard screen and 150×200 CSS px on a 2× (Retina-class) screen; at 72 DPI the same pixels span 4.2×5.6 inches.
Decoded for editing it occupies 469 KB of memory (4 bytes per pixel); uncompressed 24-bit RGB would be 352 KB, which is why the downloadable JPEG, PNG or WebP is far smaller.
Getting 300×400 from a phone, camera or screenshot
Filling 300×400 from a vertical phone video frame (1080×1920, 9:16) loses the least (25%); a Full HD screenshot (1920×1080, 16:9) loses the most (57.8%). "Fit inside" keeps the whole picture instead and the file comes out at the size in the last column; "Pad with colour" adds bars to reach the full 300×400. From the phone photo PixelFit takes the 2268×3024 crop through 1134×1512 and 567×756 before the last step to 300×400, so each pass blends neighbouring pixels instead of skipping them.
| Starting image | Crop to fill keeps | Area lost | Scale | Fit inside gives |
|---|---|---|---|---|
| 12 MP phone photo (4032×3024, 4:3) | 2268×3024 (left and right cut) | 43.8% | 0.132× (reduced) | 300×225 |
| 24 MP camera photo (6000×4000, 3:2) | 3000×4000 (left and right cut) | 50% | 0.1× (reduced) | 300×200 |
| Full HD screenshot (1920×1080, 16:9) | 810×1080 (left and right cut) | 57.8% | 0.37× (reduced) | 300×169 |
| Vertical phone video frame (1080×1920, 9:16) | 1080×1440 (top and bottom cut) | 25% | 0.278× (reduced) | 225×400 |
How many KB is a 300×400 image?
Estimated from encodes of real sample images measured with sharp 0.35.5 / libvips 8.18.7 on 31 October 2026, interpolated to 120,000 pixels. The outdoor photo at 300×400 is about 30.2 KB at quality 75 and a scanned page about 20.6 KB; your file will differ with detail and noise.
| Image type | JPEG q60 | JPEG q75 | JPEG q90 | WebP q75 | PNG |
|---|---|---|---|---|---|
| Portrait photo | ≈ 15.7 KB | ≈ 20.1 KB | ≈ 32.3 KB | ≈ 13.4 KB | ≈ 179 KB |
| Outdoor photo | ≈ 22.5 KB | ≈ 30.2 KB | ≈ 49.4 KB | ≈ 26.4 KB | ≈ 232 KB |
| Scanned document | ≈ 15.4 KB | ≈ 20.6 KB | ≈ 34.4 KB | ≈ 15.6 KB | ≈ 172 KB |
| Flat graphic or logo | ≈ 7.2 KB | ≈ 9.1 KB | ≈ 13.7 KB | ≈ 5.7 KB | ≈ 16.1 KB |
Will a 300×400 photo fit an upload limit?
The highest JPEG or WebP quality that stays under each limit at exactly 300×400 px, from the same measurements. Set the KB limit next to the pixel size and PixelFit runs this search on your own photo.
| Limit | Portrait, JPEG | Outdoor photo, JPEG | Outdoor photo, WebP |
|---|---|---|---|
| Under 10 KB | does not fit even at quality 30 | does not fit even at quality 30 | does not fit even at quality 30 |
| Under 20 KB | up to quality 73 | up to quality 50 | up to quality 48 |
| Under 30 KB | up to quality 87 | up to quality 73 | up to quality 78 |
| Under 50 KB | fits at quality 95 | up to quality 89 | up to quality 91 |
Is 300×400 good for print?
Pixels carry no physical size until you pick a DPI. At 300 DPI, the resolution PixelFit uses for its print and ID photo sizes, 300×400 covers 1×1.33 in; at 150 DPI the same pixels stretch to 2×2.67 in with half the density.
| Resolution | Print size (inches) | Print size (cm) |
|---|---|---|
| 72 DPI | 4.17×5.56 in | 10.6×14.1 cm |
| 96 DPI | 3.13×4.17 in | 7.9×10.6 cm |
| 150 DPI | 2×2.67 in | 5.1×6.8 cm |
| 200 DPI | 1.5×2 in | 3.8×5.1 cm |
| 300 DPI | 1×1.33 in | 2.5×3.4 cm |
| 600 DPI | 0.5×0.67 in | 1.3×1.7 cm |
How 300×400 shows on common screens
Shown full screen without cropping, 300×400 is scaled by the factor below; bars fill the space where the shapes differ.
| Screen | Scale | Shown at | Bars |
|---|---|---|---|
| Laptop 1366×768 | 1.92× (enlarged) | 576×768 | 790 px left and right in total |
| Full HD 1920×1080 | 2.7× (enlarged) | 810×1080 | 1110 px left and right in total |
| QHD 2560×1440 | 3.6× (enlarged) | 1080×1440 | 1480 px left and right in total |
| 4K UHD 3840×2160 | 5.4× (enlarged) | 1620×2160 | 2220 px left and right in total |
| Phone, portrait 1080×1920 | 3.6× (enlarged) | 1080×1440 | 480 px top and bottom in total |
Other 3:4 sizes
These targets share the exact 3:4 ratio of 300×400, so resizing between them is a pure scale with nothing cropped.
| Size | Scale from 300×400 | Megapixels |
|---|---|---|
| 480×640 portrait | 1.6× | 0.31 MP |
| 600×800 portrait | 2× | 0.48 MP |
| 150×200 px photo | 0.5× | 0.03 MP |
| 768×1024 portrait | 2.56× | 0.79 MP |
| 900×1200 portrait | 3× | 1.08 MP |
| 1080×1440 portrait | 3.6× | 1.56 MP |
| 1200×1600 portrait | 4× | 1.92 MP |
| 30×40 mm photo | 1.18× | 0.17 MP |
How to resize a picture to 300×400
-
Add the picture
Drop, paste or pick the photo in the PixelFit panel at the top of this page; it is decoded in your browser and never uploaded.
-
Set the size
Enter 300 as the width and 400 as the height in pixels (the panel is already set to 300×400).
-
Choose how it fits
Choose crop to fill to keep the 3:4 frame without stretching (a phone photo loses 43.8%, left and right cut). Fit inside keeps the whole picture as a 300×225 file instead; Pad with colour puts that on a full 300×400 canvas.
-
Pick the format and download
Choose JPG or WebP; without a KB limit PixelFit saves JPG at quality 85, about 40.4 KB for a detailed outdoor photo. Add a KB limit if the upload has one or the file should be smaller, then download the 300x400 file.
Sources
- Measured by PixelFit with sharp 0.35.5 / libvips 8.18.7 on 31 October 2026, from the sample photo Hartz Lake at Hartz Mountain.jpg by JustinH (Wikimedia Commons user) (CC0 1.0): commons.wikimedia.org/wiki/File:Hartz_Lake_at_Hartz_Mount…
Frequently asked questions
How do I resize an image to 300x400?
Open the image in the PixelFit panel on this page, set 300 × 400 px, choose crop to fill so nothing is stretched and download. From a 12 MP phone photo that crops 43.8% (left and right cut) and scales the rest by 0.132×.
What aspect ratio is 300x400?
300x400 has an aspect ratio of 3:4: portrait, width ÷ height = 0.75. Sizes with the same ratio include 480×640 portrait, 600×800 portrait and 150×200 px photo.
Is 300x400 good for print?
At 300 DPI 300x400 prints 1×1.33 in (2.5×3.4 cm), smaller than a passport photo, so it is a screen size rather than a print size. At 150 DPI it stretches to 2×2.67 in.
How big is a 300x400 JPEG file?
For a detailed outdoor photo about 30.2 KB at quality 75 (22.5 KB at 60, 49.4 KB at 90, 40.4 KB at the panel's default quality 85); a head-and-shoulders portrait is about 20.1 KB at quality 75, estimated from measured encodes. A flat graphic is smaller, a noisy low-light photo larger.
How does 300x400 look on a high-density screen?
On a 2× screen 300x400 is sharp when shown at 150×200 CSS px; shown larger, the browser enlarges it. A slot of 300×400 CSS px on a 2× screen needs a 600×800 file.
Related
Same 3:4 ratio
Nearby sizes
- 25×35 mm photo 5:7
- 400×514 px photo 200:257 (about 7:9)
- 35×45 mm passport photo 7:9
- 420×540 px photo 7:9
- 420×525 px photo 4:5
- 33×48 mm photo 130:189 (1:1.45)