GB to MB Converter (Gigabytes to Megabytes)
1 GB = 1024 MB. Multiply gigabytes by 1024 to get megabytes. Use the live converter above for instant results, or apply the simple formula when you are offline. Inverse: GB = MB ÷ 1024.
Formula
- MB = GB × 1024
- GB = MB ÷ 1024
- 1024 = 210 (binary step). Two steps down from GB to MB (GB→MB) is one binary step (×1024).
Quick Reference
0.25 GB = 256 MB
0.5 GB = 512 MB
1 GB = 1024 MB
2 GB = 2048 MB
4 GB = 4096 MB
8 GB = 8192 MB
How to Convert (3‑Step)
- Write the GB value (e.g., 3.5).
- Multiply by 1024.
- Result is MB (3.5 × 1024 = 3584 MB).
Why 1024? Storage math in operating systems follows binary (powers of 2). Marketing specs sometimes use decimal (1 GB = 1000 MB), which is why capacity shown by your OS can look smaller.
Common Uses
- Estimating application download sizes.
- Summing project/media folders.
- Sizing database exports or backups.
- Choosing cloud storage tiers.
Accuracy & Tips
- Use binary (1024) for OS/file manager numbers.
- Use decimal (1000) only if a vendor explicitly does.
- Round to whole MB for quick planning; keep 2–3 decimals for logs.
- Filesystems reserve overhead; provision a buffer (≈5%).
Worked Examples
- 1.25 GB → 1.25 × 1024 = 1280 MB
- 6 GB → 6 × 1024 = 6144 MB
- 5120 MB → 5120 ÷ 1024 = 5 GB
FAQ
Is 1 GB exactly 1024 MB? Yes in binary (the standard your OS uses). Decimal marketing may say 1000.
Why does my 32 GB drive show less? Manufacturer used decimal; OS reports binary.
Quick mental tip: Halve or double known pairs (e.g., 4 GB = 4096 MB so 2 GB = 2048 MB, 8 GB = 8192 MB).
Need the reverse? Enter MB above and switch units—conversion updates instantly.