Texture memory calculator
Textures are the biggest user of video memory in most games. Enter a texture size and format to see how much VRAM it takes, with or without mipmaps, and total it for any number of textures.
How texture memory is calculated
A texture is a grid of pixels, and each pixel needs a certain number of bytes. Multiply the width by the height by the bytes per pixel and you have the memory for the base image. A 4,096 by 4,096 texture stored as uncompressed 8-bit RGBA uses four bytes per pixel, which is 64 mebibytes. Mipmaps, the smaller pre-filtered copies the graphics card uses for distant surfaces, add roughly one third more, so the full chain is about 85 mebibytes.
The same texture in a block-compressed format such as BC7 uses one byte per pixel, so it takes 16 mebibytes, or about 21 with mipmaps. Compression is the main reason modern games can show so many detailed surfaces within the memory of a graphics card.
Memory for common texture sizes
Sizes are for one texture including mipmaps, in mebibytes. A mebibyte is 1,048,576 bytes.
| Size | BC1 (0.5 B) | BC7 (1 B) | RGBA8 (4 B) |
|---|---|---|---|
| 1024 x 1024 | 0.67 MiB | 1.33 MiB | 5.33 MiB |
| 2048 x 2048 | 2.67 MiB | 5.33 MiB | 21.33 MiB |
| 4096 x 4096 | 10.67 MiB | 21.33 MiB | 85.33 MiB |
| 8192 x 8192 | 42.67 MiB | 85.33 MiB | 341.33 MiB |
Why texture settings change VRAM use so much
Texture quality settings in games usually choose which mip level to keep resident, or the resolution of the texture set. Dropping one step often halves the width and height, which cuts texture memory to a quarter. That is why lowering texture quality is the quickest way to stop a game running out of video memory, and why it often has little effect on frame rate: the graphics card does the same shading work, but needs less space to hold the data.
Scenes use hundreds or thousands of textures, but never all at once. Engines stream the ones that are needed and evict the rest. This calculator shows the cost of a set of textures if all were resident, which is useful for budgeting an asset pack or understanding why a large setting needs a large card.
Using the numbers
If you build levels or mods, use the calculator to budget memory for a material set: albedo, normal, roughness and so on. If you play games, use it to understand why a texture pack asks for a big card. Pair the result with the VRAM calculator, which estimates total use at your resolution, and read how much VRAM you need for gaming for guidance on card sizes.
Remember that textures are only part of video memory. Render targets, geometry, ray tracing structures and the operating system all take space too, so leave headroom when choosing a card.
How to use the texture memory calculator
- Enter the width and height of your texture.
- Choose the format. Most game textures use a compressed format.
- Leave mipmaps on unless the texture has none.
- Enter how many textures share that size and read the total.
- Compare with your card memory using the VRAM calculator.
Common mistakes to avoid
- Forgetting mipmaps, which add about one third.
- Using uncompressed sizes for textures that ship compressed.
- Assuming every texture is in memory at once. Engines stream them.
Related tools and guides
Keep going with these: VRAM calculator, GPU memory bandwidth calculator, best graphics settings generator, RAM for gaming calculator, how much VRAM you need for gaming.
Frequently asked questions
How much VRAM does a 4K texture use?
A 4096 by 4096 texture uses 64 mebibytes uncompressed at four bytes per pixel, about 85 with mipmaps. With BC7 compression at one byte per pixel it takes 16 mebibytes, or about 21 with mipmaps. Game engines mostly use compressed formats.
What are mipmaps?
Mipmaps are a chain of smaller copies of a texture, each half the width and height of the last. The graphics card picks the right size for distant surfaces, which looks better and runs faster. The whole chain adds about one third to the memory of the base texture.
Why does lowering texture quality save so much VRAM?
Lower texture settings use smaller textures or drop the largest mip levels. Halving width and height cuts a texture to a quarter of the memory, so one step down can free a lot of space while changing frame rate very little.
Do compressed textures look worse?
Block compression is lossy, but formats such as BC7 are tuned to look very close to the original for most game art. BC1 and BC4 save more space with more visible artefacts on some images. Engines pick formats to balance quality and memory.
Are all textures in VRAM at once?
No. Engines stream the textures needed for the current view and evict others. A game can have many gigabytes of textures on disk while using less in memory. Running out of space forces streaming that shows up as stutter or blurry textures.
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