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Resize an image to 400×300 pixels
To resize an image to 400×300 px, enter 400 × 300 px and pick crop to fill so the 4:3 frame is not stretched: a 4:3 phone photo already has this shape and is only scaled by 0.099×. 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).
400×300 px
JPG · no file-size limit · 400x300 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.
400×300 at a glance
| Pixel size | 400×300 px (120,000 pixels) |
|---|---|
| Aspect ratio | 4:3, landscape (width ÷ height = 1.3333) |
| Megapixels | 0.12 MP |
| Decoded in memory | 469 KB RGBA · 352 KB RGB |
| Sharp on screen at | 400×300 CSS px at 1×, 200×150 at 2×, 133×100 at 3× density |
| Print size at 300 DPI | 1.33×1 in (3.4×2.5 cm) |
| Estimated JPEG (outdoor photo, quality 75) | 30.2 KB |
| JPEG without a KB limit (panel default, quality 85) | 40.4 KB |
What 400×300 means in pixels
400×300 is a landscape frame, 1.33 times as wide as it is tall, 120,000 pixels in total (0.12 megapixels). Its sides reduce to 4:3 (1.3333 as a decimal), so any picture cropped to 4:3 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 400×300 CSS px on a standard screen and 200×150 CSS px on a 2× (Retina-class) screen; at 72 DPI the same pixels span 5.6×4.2 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 400×300 from a phone, camera or screenshot
Filling 400×300 from a 12 MP phone photo (4032×3024, 4:3) loses nothing; a vertical phone video frame (1080×1920, 9:16) 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 400×300. From the phone photo PixelFit takes the 4032×3024 crop through 2016×1512, 1008×756 and 504×378 before the last step to 400×300, 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) | 4032×3024 (nothing cut) | 0% | 0.099× (reduced) | 400×300 |
| 24 MP camera photo (6000×4000, 3:2) | 5333×4000 (left and right cut) | 11.1% | 0.075× (reduced) | 400×267 |
| Full HD screenshot (1920×1080, 16:9) | 1440×1080 (left and right cut) | 25% | 0.278× (reduced) | 400×225 |
| Vertical phone video frame (1080×1920, 9:16) | 1080×810 (top and bottom cut) | 57.8% | 0.37× (reduced) | 169×300 |
How many KB is a 400×300 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 400×300 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 400×300 photo fit an upload limit?
The highest JPEG or WebP quality that stays under each limit at exactly 400×300 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 400×300 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, 400×300 covers 1.33×1 in; at 150 DPI the same pixels stretch to 2.67×2 in with half the density.
| Resolution | Print size (inches) | Print size (cm) |
|---|---|---|
| 72 DPI | 5.56×4.17 in | 14.1×10.6 cm |
| 96 DPI | 4.17×3.13 in | 10.6×7.9 cm |
| 150 DPI | 2.67×2 in | 6.8×5.1 cm |
| 200 DPI | 2×1.5 in | 5.1×3.8 cm |
| 300 DPI | 1.33×1 in | 3.4×2.5 cm |
| 600 DPI | 0.67×0.5 in | 1.7×1.3 cm |
How 400×300 shows on common screens
Shown full screen without cropping, 400×300 is scaled by the factor below; bars fill the space where the shapes differ.
| Screen | Scale | Shown at | Bars |
|---|---|---|---|
| Laptop 1366×768 | 2.56× (enlarged) | 1024×768 | 342 px left and right in total |
| Full HD 1920×1080 | 3.6× (enlarged) | 1440×1080 | 480 px left and right in total |
| QHD 2560×1440 | 4.8× (enlarged) | 1920×1440 | 640 px left and right in total |
| 4K UHD 3840×2160 | 7.2× (enlarged) | 2880×2160 | 960 px left and right in total |
| Phone, portrait 1080×1920 | 2.7× (enlarged) | 1080×810 | 1110 px top and bottom in total |
Other 4:3 sizes
These targets share the exact 4:3 ratio of 400×300, so resizing between them is a pure scale with nothing cropped.
| Size | Scale from 400×300 | Megapixels |
|---|---|---|
| 320×240 (QVGA) | 0.8× | 0.0768 MP |
| 640×480 (VGA) | 1.6× | 0.31 MP |
| 800×600 (SVGA) | 2× | 0.48 MP |
| 1000×750 landscape | 2.5× | 0.75 MP |
| 1024×768 (XGA) | 2.56× | 0.79 MP |
| 1200×900 landscape | 3× | 1.08 MP |
| 1280×960 landscape | 3.2× | 1.23 MP |
| 1600×1200 (UXGA) | 4× | 1.92 MP |
How to resize a picture to 400×300
-
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 400 as the width and 300 as the height in pixels (the panel is already set to 400×300).
-
Choose how it fits
Choose crop to fill: a 4:3 phone photo already matches, so nothing is cut.
-
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 400x300 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 400x300?
Open the image in the PixelFit panel on this page, set 400 × 300 px, choose crop to fill so nothing is stretched and download. From a 12 MP phone photo that only scales the picture and scales the rest by 0.099×.
What aspect ratio is 400x300?
400x300 has an aspect ratio of 4:3: landscape, width ÷ height = 1.3333. Sizes with the same ratio include 320×240 (QVGA), 640×480 (VGA) and 800×600 (SVGA).
Is 400x300 good for print?
At 300 DPI 400x300 prints 1.33×1 in (3.4×2.5 cm), smaller than a passport photo, so it is a screen size rather than a print size. At 150 DPI it stretches to 2.67×2 in.
How big is a 400x300 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 400x300 look on a high-density screen?
On a 2× screen 400x300 is sharp when shown at 200×150 CSS px; shown larger, the browser enlarges it. A slot of 400×300 CSS px on a 2× screen needs an 800×600 file.
Related
Same 4:3 ratio
Nearby sizes
- 336×280 banner 6:5
- 300×250 banner 6:5
- 400×400 square 1:1
- 300×300 square 1:1
- 35×35 mm photo 1:1
- 300×200 landscape 3:2