Data Size Converter

Converts data sizes across bytes, KB, MB, GB, TB and PB using the binary convention — each step is 1,024, so 1 GB here is 1,073,741,824 bytes. The convention operating systems have traditionally used for file and memory sizes.

How to use

1. Enter a size in any unit.
2. Read the equivalents across the other units.
3. Divide a total by a per-file size to estimate how many files fit.
4. When a number seems off by a few percent, check whether its source used 1,000-based units.

When you actually need this

• Working out how many photos or videos fit on a card or drive.
• Comparing a download's size against remaining disk space.
• Estimating transfer time from a file size and connection speed.
• Reconciling a drive advertised in GB with what the OS reports.

Why a 1 TB drive shows as 931 GB

Storage marketing counts in decimal — 1 TB as one trillion bytes — while operating systems traditionally count in binary, dividing by 1,024 at each step. One trillion bytes divided by 1,024⁴ is 0.909 TiB, displayed as roughly 931 GB: nothing is missing, the units differ. The gap compounds with scale — about 2.4% at the megabyte level, 9.9% at the terabyte level. Standards bodies assign KiB/MiB/GiB to the binary steps, but everyday usage still says KB/MB/GB for both, so the safest habit with contracts and capacity planning is to check which convention a number uses before comparing it to another.

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FAQ

How precise are the conversion factors in Data Size Converter?

The factors are the internationally defined exact values — one inch is exactly 25.4 millimetres, one pound is exactly 0.45359237 kilograms, and so on. Results are computed at full floating-point precision and only rounded for display.

Can I convert between metric and imperial units in both directions?

Yes. Enter a value in any field and every other unit updates at once, so the conversion works in either direction without switching modes or pressing a button.

Why does the last decimal place sometimes look off?

Because many conversions are irrational in decimal form and browsers use binary floating point, the final digit can differ by a tiny amount. The displayed value is rounded sensibly for everyday use; for laboratory or engineering work, carry the unrounded figure through your own calculation.