Convert between bits, bytes, KB, MB, GB, and TB — with binary (1024) steps shown and decimal (1000) explained.
Why does a “1 TB” drive show only 931 GB in Windows? Because two different definitions of “gigabyte” are fighting: drive makers use decimal gigabytes (1,000,000,000 bytes) while operating systems use binary gibibytes (1,073,741,824 bytes). Our free Digital Storage Converter converts between bits, bytes, KB, MB, GB, and TB using the binary (1024-based) definitions your OS uses, shows the full step-by-step working, and prints a friendly human-readable size — so the mystery of the missing gigabytes finally makes sense.
Digital storage units are powers of two wearing decimal names. A bit is a single 0/1; a byte is 8 bits — enough for one text character. A kilobyte is 1024 bytes (210), a megabyte 1024 KB, a gigabyte 1024 MB, a terabyte 1024 GB. Each step multiplies by 1024, which is why storage math feels alien: 1 TB is not 1000 GB but 1024 GB, and the gaps compound at every level.
Enter any size, choose the units, and the converter walks through the byte base — the one unit everything converts through — then lands on your target, with a friendly-size readout for sanity. Students, IT buyers, photographers sizing memory cards, and anyone who has ever wondered where their disk space went will find the steps transparent and the answers exact.
The bit (binary digit) is the atom of computing — one 0 or 1. Eight bits make a byte, the smallest addressable chunk of memory and enough to store one ASCII character. Everything larger is built by multiplying by 1024 (210): KB = 1024 B, MB = 1024 KB, GB = 1024 MB, TB = 1024 GB. The 1024 step is a historical accident of binary addressing that became a standard.
The binary vs. decimal war is the field’s famous confusion. Storage vendors advertise decimal units (1 GB = 109 bytes) because the numbers look bigger; operating systems report binary units (1 GiB = 230 bytes) because memory addressing is binary. A “1 TB” drive holds 1012 bytes, which Windows divides by 240 and reports as 931 “GB” — no space is missing, only the yardstick changed. The IEC created kibibyte/mebibyte/gibibyte (KiB, MiB, GiB) to end the ambiguity, but everyday language still says KB/MB/GB for the binary values — which is what this converter uses, matching your OS.
Bits vs. bytes trips everyone up in networking: ISPs sell megabits per second (Mbps), while downloads display megabytes per second (MB/s) — a factor of 8 apart. A “100 Mbps” connection downloads at 12.5 MB/s at best. The converter includes bits precisely so you can translate the ISP’s number into the download dialog’s number.
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All conversions pass through raw bytes, exactly as the widget’s step line shows. These are the binary (1024) definitions used by operating systems; decimal drive-maker definitions divide by 1000 at each step instead.
A new drive is labeled 2 TB (decimal). How much does Windows report?
This single calculation ends the most common storage argument in IT. The converter’s friendly-size line performs the same translation for any input.
How long to download a 4.7 GB (binary) DVD image at 50 Mbps?
Notice the bit/byte factor of 8 doing the heavy lifting — forgetting it is the classic error, and the converter keeps bits and bytes in separate, labeled units so you can’t mix them.
Jonas shoots weddings: 2,000 RAW photos at ~30 MB each. That’s 60,000 MB — but is it 60 GB? He converts: 60,000 MB ÷ 1024 = 58.59 GB. A 64 GB card (decimal: 64 × 109 bytes = 59.6 binary GB) holds it with 1 GB to spare — uncomfortably tight. He buys 128 GB instead. The converter turned a vague worry into a purchase decision with a number attached.
The binary/decimal gap matters most at card and drive boundaries: a “128 GB” card is 119.2 binary GB, a “256 GB” SSD is 238.4. Professionals who learned this the hard way — mid-shoot “card full” — now convert before they buy.
A second scenario: backups. A small business has 3.5 TB of data (binary, per the OS) and shops for cloud backup priced per decimal TB. 3.5 × 240 = 3,848,764,620,800 bytes ÷ 1012 = 3.85 decimal TB — they need the 4 TB tier, not 3.5. The 10% gap between the two definitions is a billing tier.
A third: video. A 4K camera records at 400 Mbps. One hour is 400 × 3600 ÷ 8 = 180,000 MB = 175.8 GB. A 10-hour shoot needs 1.72 TB of media — two 1 TB (decimal, 931 binary GB each = 1.82 TB total) drives, exactly. The converter’s bit handling makes bitrate-to-storage math one step instead of three.
The 1024 convention was born in memory addressing: 10 address lines select 210 = 1024 locations, so early engineers called 1024 bytes a “kilobyte” — close enough to 1000 to borrow the Greek prefix. The approximation stuck for decades because the 2.4% error didn’t matter when memories were kilobytes; at terabytes it has compounded to 10%, and the lawsuits followed.
The IEC’s 1998 fix — kibibyte (KiB), mebibyte (MiB), gibibyte (GiB) — is technically correct and widely ignored outside Linux and engineering documents. Windows still says “GB” for GiB; macOS switched to decimal in 2009, so the same drive shows different numbers on the two OSes. The converter sidesteps the politics by labeling its math: binary, 1024-based, OS-style.
Networking standardized on decimal long ago: 1 Gbps Ethernet = 109 bits/s, no ambiguity. That is why the bit/byte divide and the binary/decimal divide so often collide in download-time math — you are converting across both at once. The widget handles the bit factor explicitly in its step line so the two conversions never get tangled.
Storage density’s march gives the units cultural meaning: a 1981 IBM PC hard drive held 10 MB — this page’s friendly-size function would call a modern photo “3,000× that drive.” By 2007 the first terabyte drive arrived; today a microSD card smaller than a fingernail holds 1 TB. Each unit — MB, GB, TB — marks an era, and the converter translates between eras.
Data-center math lives at the top of the scale: a hyperscale facility with 100 PB (petabytes) is 100 × 250 bytes — about 112.6 decimal PB of raw disks before redundancy. Capacity planners convert constantly between the binary numbers their filesystems report and the decimal numbers their purchase orders use; a 10% slip at that scale is millions of dollars.
Quantum and DNA storage may eventually break the byte’s monopoly — DNA stores ~215 PB per gram in base-4 — but the bit will remain the accounting unit. Whatever the medium, “how many bits” will still be the first question, and converters like this one will still be the fastest honest answer.
One more practical pattern: always convert to bytes first, exactly as the widget does. Bytes are the universal solvent of storage math — every unit, binary or decimal, bit or byte, dissolves into bytes and recrystallizes into whatever you need. Internalize that one habit and no storage word problem can confuse you again.
Digital storage converter (binary 1024-based, OS-style): bytes = value × unit-from ÷ 8; result = bytes × 8 ÷ unit-to. 1 KB=1024 B, 1 MB=1024 KB, 1 GB=1024 MB, 1 TB=1024 GB, 1 B=8 b. Decimal drive sizes read ~7-10% smaller in binary. Source: Sigma Calculator, Digital Storage Converter, https://sigmacalculator.net/math-calculators/digital-storage-converter/
Cite this page as: Digital Storage Converter, Sigma Calculator, https://sigmacalculator.net/math-calculators/digital-storage-converter/
Last updated: October 12, 2026