MB to GB Converter

1. Type a size in megabytes.
2. Pick Decimal (1,000) for phone plans, drive boxes and Mac, or Binary (1,024) for Windows and RAM.
3. Read the answer, plus the other counting system, TB, KB and bytes.
4. Tap GB to MB to convert the other way, then type the size in gigabytes.

A megabyte (MB) and a gigabyte (GB) measure digital storage. A gigabyte is about a thousand megabytes.

There are two ways to count. In the decimal system, 1 GB = 1,000 MB. Phone carriers, drive makers and macOS use it. In the binary system, 1 GB = 1,024 MB. Windows and RAM sizes use it. The binary units are properly called GiB and MiB.

Computers store data in powers of two, so binary units step by 1,024. Decimal units follow the metric system and step by 1,000.

Going the other way? Use the GB to MB converter.

Typical sizes, so you can estimate how much space you need. Real files vary with quality and compression.

One gigabyte holds about 300 phone photos, 250 songs or roughly 20 minutes of HD video recorded on a phone.

On a phone plan, 1 GB covers about 3 hours of web browsing, 20 minutes of HD streaming or 10 hours of music streaming. Video uses data fastest, so lower the streaming quality to make a plan last longer.

To see how many MB you have left, divide by 1,000 for carrier plans. A 15 GB plan gives you 15,000 MB.

That gap is why a new "1 TB" drive shows about 931 GB in Windows. Nothing is missing; it is counted two ways.

The Counting System

At GB size the gap is about 7 percent. At TB size it grows to about 10 percent.

Bits vs Bytes

Internet speeds use megabits (Mb), not megabytes (MB). 8 bits make a byte, so 100 Mbps is about 12.5 MB per second.

Formatting and System Files

A drive shows less free space than its size because the system uses some of it.

Phone Data Plans

See how many MB a 5 GB plan gives you.

Email and Upload Limits

Check if a file fits a 25 MB email limit or a 2 GB upload cap.

Buying Storage

Work out how many GB your photos and videos need.

1. Mixing Up Mb and MB

A small b means bits. A big B means bytes. 1 MB is 8 Mb.

2. Using 1,024 for Data Plans

Carriers use 1,000. Use the decimal setting for plans.

3. Thinking a Drive Is Short

A 500 GB drive showing 465 GB in Windows is normal; that is binary counting.

Both systems are exact by definition, so the math is exact. Only the display is rounded.

Divide the MB by 1,000. For example, 2,500 MB is 2.5 GB. Windows divides by 1,024 instead.

Both are used. 1 GB is 1,000 MB in the decimal system and 1,024 MB in the binary system.

1,000 MB in decimal units, or 1,024 MB in binary units.

500 MB is 0.5 GB in decimal units, or about 0.49 GB in binary units.

Yes. 1 GB is about twice as big as 500 MB.

The box counts 1 TB as 1,000,000,000,000 bytes. Windows divides by 1,024 three times, which gives about 931 GB.

MB is megabytes and Mb is megabits. One megabyte is 8 megabits.

About 300 phone photos at roughly 3 MB each.

A gibibyte is the binary gigabyte, exactly 1,024 MiB. Windows labels it GB.

• Prefixes for binary multiples (NIST).
• The International System of Units (SI brochure) (International Bureau of Weights and Measures).
• Unit conversion (US National Institute of Standards and Technology).