Your new phone says 128 GB on the box, but the settings screen shows barely 110 GB free. Your 1 TB hard drive appears as 931 GB in Windows. Nothing is broken and no space has vanished — this is the oldest confusion in computing: storage units can be counted two different ways. Our data storage converter translates between kilobytes (KB), megabytes (MB), gigabytes (GB), terabytes (TB) and petabytes (PB) using the decimal system, the same system manufacturers use on their packaging. Type a value, pick the units, and see the exact equivalent instantly.
Knowing real conversions helps you make better buying decisions. Is a 256 GB laptop enough for your photo library? Will a 4 TB external drive hold your video backups? How much of a 2 GB daily data pack does one long video call actually eat? Quick, honest conversions turn vague storage numbers into answers you can act on — before you spend money on a bigger plan or a bigger drive you may not need.
Students use it to check whether project files will fit on a pen drive, photographers use it to estimate how many memory cards a shoot needs, and shoppers use it to compare phones and laptops on equal terms. The converter runs entirely in your browser, needs no sign-up, and gives the same result every time — because the maths of unit conversion never changes.
How it works
The tool uses the decimal (SI) system, where each step up multiplies by 1,000: 1,000 KB make 1 MB, 1,000 MB make 1 GB, 1,000 GB make 1 TB, and 1,000 TB make 1 PB. This is the system hard-drive makers, phone companies, and internet providers use when they advertise capacities. To convert, the tool first expresses your value in bytes, then multiplies or divides by the right power of 1,000 to reach the target unit.
Your computer may show a different number for the same drive, and that is expected. Operating systems like Windows traditionally measure storage in binary units, where each step multiplies by 1,024 instead of 1,000 — so what Windows calls a GB is really a gibibyte (GiB). A drive sold as 500 GB holds 500 billion bytes, which works out to about 465 GiB. Same drive, different ruler.
When you enter a value and choose the from and to units, the tool applies the exact power-of-1,000 factor between them. There is no estimation involved — unit conversion is pure arithmetic — so the numbers shown are exact within the decimal system.
How to use this tool
- Type the storage value you want to convert, for example 500.
- Choose the unit you are converting from — KB, MB, GB, TB or PB.
- Choose the unit you want the answer in.
- Click Convert to see the exact equivalent instantly.
- Compare the result with your device's free space or a product's specifications.
- For internet speeds, remember providers quote megabits (Mb), not megabytes (MB).
Practical tips
- Do not mix up MB (megabytes, for storage) and Mb (megabits, for broadband) — 1 byte equals 8 bits, so a 100 Mbps plan downloads at about 12.5 MB per second.
- If Windows shows less than the box promised, divide the advertised GB by 1.073 to predict the Windows figure.
- Phone 'system' storage is genuinely used space — check the storage breakdown in settings rather than converting units.
- Keep 15–20 percent of any drive free; full drives slow down and leave no room for updates.
- When comparing phones, convert everything to GB first — 0.12 TB versus 128 GB trips people up.
Frequently asked questions
Why does Windows show less storage than the box says?
Manufacturers use the decimal system (1 GB = 1,000 MB) while Windows measures with the binary system (1 GiB = 1,024 MiB) but still labels it GB. A 500 GB drive holds 500 billion bytes, which Windows reports as about 465 GB. Nothing is missing — the two systems simply count differently.
Is this converter decimal or binary based?
This converter uses the decimal system (1 KB = 1,000 bytes), matching how storage products are marketed and how phone storage is described. If your operating system shows different numbers, it is likely using binary units instead — the same drive measured with a different ruler. Check which system your device uses before comparing figures.
How many photos fit in 128 GB?
It depends on photo size. A typical 12 MP phone photo is 3–5 MB, so 128 GB holds roughly 25,000–40,000 photos. Convert your free space to megabytes with this tool, then divide by your average photo size. RAW files are far larger, so the same space holds far fewer. Screenshots and WhatsApp images are much smaller, so they barely dent the total.
What is the difference between MB and Mb?
Capital B means bytes and small b means bits — one byte equals 8 bits. Storage uses bytes; internet speeds use bits. A 100 Mbps connection downloads at about 12.5 MB per second. Always divide the bits figure by 8 for the real speed. This single conversion explains most 'slow internet' confusion.
How many GB is a two-hour HD movie?
A two-hour 1080p movie is typically 3–6 GB, while 4K can be 15–25 GB. Convert your free space to GB with this tool and divide by the per-movie size. Lower streaming quality settings use far less — under 1 GB for the same film. Downloaded files stay on the device until you delete them.
Can I use this for mobile data packs?
Yes. Indian mobile plans quote data in decimal GB, so conversions match your pack exactly. For example, 1.5 GB per day equals 1,500 MB — roughly 3 hours of standard-definition video. Background updates consume data too, so treat that as a best case. Streaming music uses far less — roughly 50 MB per hour.
Note: Conversions use the decimal system (1 GB = 1,000 MB), matching how storage is marketed. Operating systems may display binary-based values that differ slightly; neither figure is wrong.