Storage units are everywhere: your phone says it has 128 GB, your laptop ships with 16 GB of RAM, your internet plan promises 500 MB per second, and a new external drive costs about $60 for 2 TB. But are all those numbers measured on the same scale? This data storage converter takes any amount in bytes, kilobytes, megabytes, gigabytes, or terabytes and instantly re-expresses it in every other unit, so you can compare drives, estimate download times, and stop guessing whether a "1 TB" drive really holds 1,000 or 1,024 gigabytes.
The engine below uses the binary (JEDEC) convention — 1 KB = 1,024 bytes, 1 MB = 1,024 KB, 1 GB = 1,024 MB, 1 TB = 1,024 GB — which is the scale Windows, macOS Finder, RAM sizing, and most file managers report.
How to Use
- Enter the Storage Value you want to convert. For example, if a file is listed as 4,096 MB and you want to know how many gigabytes that is, type 4096.
- Pick the From Unit that matches the number you typed. Common choices are gigabytes (GB) for drive capacity, megabytes (MB) for file sizes, and terabytes (TB) for external drives and cloud backups.
- Pick the To Unit you want the result expressed in. If you are comparing against a phone spec, choose gigabytes; if you are estimating RAM, choose megabytes.
- Read the result card. The Converted Value is the headline number, and the rows below show the same amount expressed in bytes, KB, MB, GB, and TB so you can cross-check against any spec sheet.
The result card rounds the headline number to four decimal places so the page stays readable; the reference rows (bytes, KB, MB, GB, TB) keep the same precision. If you need more digits for a spreadsheet, multiply through by the 1,024-based factors listed above.
The Binary vs. Decimal Debate
Drive manufacturers (Seagate, Western Digital, Samsung) advertise capacity in decimal units: 1 GB = 1,000 MB, 1 TB = 1,000 GB. Operating systems, however, count in binary units: 1 GiB = 1,024 MiB, and Windows labels those "GB." That mismatch is why a drive sold as 1 TB shows up in Windows as roughly 931 GB rather than 1,000 GB.
This converter uses the binary scale (1 KB = 1,024 B) because that is what your computer actually reports. If you need the decimal figure a drive vendor advertises, multiply the binary result by about 1.024³ (roughly 1.074) when moving from GB to the advertised "GB" claim. The two numbers are never the same, and knowing which one you are looking at prevents a lot of confusion at the store.
The full conversion table used by this page:
- 1 Kilobyte (KB) = 1,024 Bytes
- 1 Megabyte (MB) = 1,024 KB = 1,048,576 Bytes
- 1 Gigabyte (GB) = 1,024 MB = 1,073,741,824 Bytes
- 1 Terabyte (TB) = 1,024 GB = 1,099,511,627,776 Bytes
Examples
Example 1 — Sizing a photo library. A photographer estimates 25,000 RAW photos at roughly 25 MB each, which is about 625,000 MB total. Converting that number shows it equals roughly 610 GB (or 0.6 TB). That means a $60 1 TB portable drive leaves about 40% headroom for a second backup, while a 512 GB SSD would fill up before the project ends.
Example 2 — Comparing two external drives. Drive A is advertised as 2 TB and costs $80; Drive B is advertised as 4 TB and costs $130. In binary units, 2 TB is about 2,048 GB and 4 TB is about 4,096 GB. The larger drive delivers exactly twice the capacity for only 62% more money, so the per-gigabyte cost drops from about $0.039 to about $0.032. That 18% savings per gigabyte is the number that should drive the decision, not the headline "2 TB vs 4 TB" on the box.
Example 3 — Downloading a game. A new console title says it needs 84 GB of free space. On a 500 GB drive that looks like 16.8% of the disk, but once the OS itself reserves 60 GB and earlier games already fill 250 GB, the remaining 190 GB has to hold not just 84 GB but also day-one patches that can add another 10–20%. Running the numbers through this converter before you buy prevents the "disk full" surprise halfway through the install.
Example 4 — RAM vs. storage confusion. A stick of DDR5 RAM rated at 16 GB is not 16 billion bytes of "storage" in the drive sense; it is 16 GiB of volatile memory. This converter treats 16 GB of RAM as exactly 16,384 MB, which is the figure engineers use when sizing memory upgrades. If you are comparing two RAM sticks, 16 GB and 32 GB differ by 16,384 MB, not by 16,000 — the binary scale is why a "32 GB" kit shows up as 32,768 MB in your system report.
FAQ
How many megabytes are in a gigabyte?
Using the binary convention this calculator uses, there are exactly 1,024 megabytes in one gigabyte. That means 5 GB equals 5,120 MB, 16 GB equals 16,384 MB, and so on. Drive manufacturers advertising in decimal units say 1 GB = 1,000 MB, which is why a spec sheet and your file manager may disagree by about 2.4%.
Why does my 1 TB drive only show 931 GB in Windows?
Because Windows counts in binary units (1 TB = 1,024 GB) while the manufacturer advertised in decimal units (1 TB = 1,000 GB). A 1,000 GB decimal drive is about 931 binary GB. The drive is not defective; the two numbers are measured on different scales, and this converter uses the binary scale your operating system reports.
What is the difference between KB and KiB?
KB (kilobyte) historically means 1,024 bytes in computing, but the standards body IEC introduced KiB (kibibyte) to mean exactly 1,024 bytes and reserved KB for the decimal 1,000 bytes. Most consumer software still labels 1,024 bytes as "KB," which is what this calculator follows. If you need the strictly standard notation, treat the output KB, MB, GB on this page as KiB, MiB, GiB.
How do I convert bits to bytes?
There are 8 bits in 1 byte. If your internet speed is quoted as 100 megabits per second (Mbps), that is 12.5 megabytes per second (MB/s). To convert bits to bytes, divide by 8. To go the other way, multiply by 8. This does not change the byte-to-GB math; it only affects whether you are measuring the wire speed or the file size.
How many photos or videos fit on a drive?
As a rough rule of thumb: a 12 MP JPEG photo is about 3–5 MB, a RAW photo is 25–50 MB, and a one-minute 4K video is roughly 400 MB. A 1 TB drive (1,024 binary GB) holds about 200,000 JPEGs or 2,500 minutes of 4K video. Use this converter to turn your own average file size into a total-count estimate before you shop.
Is this converter accurate for RAM sizes?
Yes. Memory modules are always specified in binary units: 8 GB of RAM is exactly 8,192 MB, and 16 GB is 16,384 MB. The decimal-vs-binary mismatch only appears on drive packaging, not on RAM sticks, so the figures this page returns for RAM match what your motherboard BIOS will report.
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Disclaimer
This data storage converter is provided for informational purposes only and does not constitute engineering, procurement, or financial advice. Conversion results are based on the binary 1024-based convention used by most consumer operating systems; drive vendors, cloud providers, and networking equipment may use decimal (1000-based) units. Always confirm the exact unit convention with your hardware manufacturer or service provider before making a purchase, capacity-planning, or budgeting decision. For our editorial standards see the About page, and for data handling see the Privacy Policy; we do not store the values you convert on this page.