Data Size Converter

Live SI vs IEC dual ladder so one storage magnitude shows both decimal drive-label spelling and binary OS/RAM spelling, plus the marketing gap between them.

Educational unit naming only. Not a free-space, filesystem, partition, or RAID capacity audit. Vendor stickers and OS views may use different families on purpose.

By Ahmet C. Toplutaş·Site owner & editor · Technology tools

Last updated May 21, 2026 · Reviewed May 21, 2026 · Planning estimates only - not tax, medical, or investment advice

Same bits, two naming families

Storage sizes are one bit count spoken in two dialects. SI decimal prefixes (kB, MB, GB, TB) step by 1000. IEC binary prefixes (KiB, MiB, GiB, TiB) step by 1024. Drive stickers often use the decimal family; many operating systems and RAM modules lean binary.

This page’s framing is SI vs IEC ladders for one magnitude, with a marketing gap peel. It is storage naming literacy, not a base-digit nibble strip and not a density solve-for triad.

Decision framing: “Is this label a 1000-based marketing size, or a 1024-based OS/RAM size, and what does the other family report for the same bits?”

SI vs IEC dual board

Enter one value and unit. The dual board fills every SI rung and every IEC rung from the same underlying bit count. Focus rows highlight the prefix closest to your input so you can compare GB against GiB without losing the rest of the ladder.

Flip Input family between SI decimal and IEC binary. Unit chips follow the family so you never “enter GiB” while claiming a decimal sticker story.

Load 1 TB drive. Read TB on the SI side and TiB on the IEC side. That pair is the classic “missing capacity” illusion.

Marketing gap peel

For the active prefix step (kilo through peta), the peel compares one SI unit to one IEC unit. A GiB holds about 7.37% more bytes than a GB. That percent is naming math, not deleted photos.

Filesystem overhead, partitions, reserved blocks, and RAID still reduce usable space on top of this naming gap. The peel isolates the prefix confusion so those other losses do not get blamed on “fake TB.”

Bit / byte strip

Eight bits make one byte on this board. File sizes are usually quoted in bytes; network rates often use bits per second. The strip shows both integer counts for the magnitude you entered so bit/byte slips stay visible.

That strip is related to, but not the same as, the base converter nibble view. Here the job is storage magnitude, not digit spelling.

What the panel actually computes

Non-negative sizes. Fractional inputs round to the nearest bit after scaling by the unit factor. Ladders go through PB / PiB for homework and planning sketches.

SI: 1 kB = 1000 B; 1 MB = 1000² B; … IEC: 1 KiB = 1024 B; 1 MiB = 1024² B; … 1 B = 8 bit 1 TB (SI) = 10¹² B ≈ 0.9095 TiB 1 TiB = 2⁴⁰ B ≈ 1.0995 TB (SI)

Where this hands off

After size naming literacy, hand off for download time, bandwidth cost, digit bases, or subnet math.

Integer bases: binary / hex / base converter
Time to pull a file: download time calculator
Pipe to invoice: bandwidth to cost
Network addressing: subnet calculator

Worked scenarios

Scenario A: 1 TB drive. Enter 1 TB (SI). IEC ladder shows about 0.909 TiB. Gap peel: GiB vs GB (or TiB vs TB) explains the sticker vs OS story.

Switch family to IEC and enter 1 TiB. SI side reads about 1.10 TB. Same teaching beat from the other direction.

Scenario B: Photo 4.2 MB. Everyday SI file size. Dual board still fills KiB/MiB so exporters speaking binary stay aligned.

Scenario C: DVD 4.7 GB. Optical-media habit uses decimal GB. Compare GiB on the right column before quoting “disk image size.”

Scenario D: 8 GiB RAM. Memory modules are binary. SI ladder shows the decimal spelling so a mixed spreadsheet does not invent capacity.

Common mistakes

Treating GB and GiB as identical labels.
Blaming “fake capacity” only on naming when partitions and filesystem overhead also shrink usable space.
Mixing bit rates (Mb/s) with byte sizes (MB) without the ×8 factor.
Using older “KB = 1024” habits while reading a decimal drive sticker.
Expecting this board to replace download time or free-space tools.
Confusing size ladders with base digit conversion.

How to use this panel

Load a scene preset or pick SI vs IEC as the input family.
Enter the value and unit.
Read both ladders, the bit/byte strip, and the marketing gap peel.
Share when you want URL state. Typing does not rewrite the address bar. Confirm critical capacity with the vendor’s stated unit family.

When not to stop at size naming

Stop here for SI vs IEC literacy. Hand off for timing, billing, or digit bases.

Download duration: download time.
Bandwidth billing: bandwidth cost.
Bases: base converter.

Frequently asked questions

What is the difference between SI and IEC size families?

SI decimal units (kB, MB, GB, TB) step by 1000. IEC binary units (KiB, MiB, GiB, TiB) step by 1024. The same bit count can be spelled both ways; the labels are not interchangeable.

Why does a 1 TB drive look smaller in the OS?

Many drive stickers use decimal TB (10¹² bytes). Many operating systems report TiB-style binary units. 1 TB ≈ 0.909 TiB, so the capacity looks “missing” even when the bytes match the sticker math.

What does the marketing gap peel show?

For the active prefix (kilo/mega/giga/tera/peta), it compares one SI unit to one IEC unit and states how many percent more bytes the binary unit holds. That is the naming gap, not file-system overhead.

Are KB and KiB the same?

Not when you follow modern prefixes. kB (or KB in casual SI talk) is 1000 bytes; KiB is 1024 bytes. Older docs often wrote KB for 1024 bytes. This board separates the families on purpose.

How is this different from the base converter?

The base converter spells one integer in binary/octal/decimal/hex digits. This page converts one storage magnitude across SI and IEC size ladders, with a bit/byte strip and marketing gap peel.

Does this measure free disk space?

No. It converts a stated size between units. Filesystem overhead, partitions, reserved blocks, and RAID are outside this board.

Bit vs byte?

Eight bits make one byte on this board. Network rates are often bits per second; file sizes are usually bytes. The strip shows both for the same magnitude.

Sources

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Same bits, two naming families

This page’s framing is SI vs IEC ladders for one magnitude, with a marketing gap peel. It is storage naming literacy, not a base-digit nibble strip and not a density solve-for triad.

Decision framing: “Is this label a 1000-based marketing size, or a 1024-based OS/RAM size, and what does the other family report for the same bits?”

SI vs IEC dual board

Flip Input family between SI decimal and IEC binary. Unit chips follow the family so you never “enter GiB” while claiming a decimal sticker story.

Load 1 TB drive. Read TB on the SI side and TiB on the IEC side. That pair is the classic “missing capacity” illusion.

Marketing gap peel

For the active prefix step (kilo through peta), the peel compares one SI unit to one IEC unit. A GiB holds about 7.37% more bytes than a GB. That percent is naming math, not deleted photos.

Bit / byte strip

That strip is related to, but not the same as, the base converter nibble view. Here the job is storage magnitude, not digit spelling.

What the panel actually computes

Non-negative sizes. Fractional inputs round to the nearest bit after scaling by the unit factor. Ladders go through PB / PiB for homework and planning sketches.

SI: 1 kB = 1000 B; 1 MB = 1000² B; … IEC: 1 KiB = 1024 B; 1 MiB = 1024² B; … 1 B = 8 bit 1 TB (SI) = 10¹² B ≈ 0.9095 TiB 1 TiB = 2⁴⁰ B ≈ 1.0995 TB (SI)

Worked scenarios

Scenario A: 1 TB drive. Enter 1 TB (SI). IEC ladder shows about 0.909 TiB. Gap peel: GiB vs GB (or TiB vs TB) explains the sticker vs OS story.

Switch family to IEC and enter 1 TiB. SI side reads about 1.10 TB. Same teaching beat from the other direction.

Scenario B: Photo 4.2 MB. Everyday SI file size. Dual board still fills KiB/MiB so exporters speaking binary stay aligned.

Scenario C: DVD 4.7 GB. Optical-media habit uses decimal GB. Compare GiB on the right column before quoting “disk image size.”

Scenario D: 8 GiB RAM. Memory modules are binary. SI ladder shows the decimal spelling so a mixed spreadsheet does not invent capacity.

Common mistakes

Treating GB and GiB as identical labels.
Blaming “fake capacity” only on naming when partitions and filesystem overhead also shrink usable space.
Mixing bit rates (Mb/s) with byte sizes (MB) without the ×8 factor.
Using older “KB = 1024” habits while reading a decimal drive sticker.
Expecting this board to replace download time or free-space tools.
Confusing size ladders with base digit conversion.

Frequently asked questions

What is the difference between SI and IEC size families?

SI decimal units (kB, MB, GB, TB) step by 1000. IEC binary units (KiB, MiB, GiB, TiB) step by 1024. The same bit count can be spelled both ways; the labels are not interchangeable.

Why does a 1 TB drive look smaller in the OS?

What does the marketing gap peel show?

Are KB and KiB the same?

Not when you follow modern prefixes. kB (or KB in casual SI talk) is 1000 bytes; KiB is 1024 bytes. Older docs often wrote KB for 1024 bytes. This board separates the families on purpose.

How is this different from the base converter?

The base converter spells one integer in binary/octal/decimal/hex digits. This page converts one storage magnitude across SI and IEC size ladders, with a bit/byte strip and marketing gap peel.

Does this measure free disk space?

No. It converts a stated size between units. Filesystem overhead, partitions, reserved blocks, and RAID are outside this board.

Bit vs byte?

Eight bits make one byte on this board. Network rates are often bits per second; file sizes are usually bytes. The strip shows both for the same magnitude.

Same bits, two naming families

SI vs IEC dual board

Marketing gap peel

Bit / byte strip

What the panel actually computes

Where this hands off

Worked scenarios

Common mistakes

How to use this panel

When not to stop at size naming

Frequently asked questions

What is the difference between SI and IEC size families?

Why does a 1 TB drive look smaller in the OS?

What does the marketing gap peel show?

Are KB and KiB the same?

How is this different from the base converter?

Does this measure free disk space?

Bit vs byte?

Sources

Same bits, two naming families

SI vs IEC dual board

Marketing gap peel

Bit / byte strip

What the panel actually computes

Where this hands off

Worked scenarios

Common mistakes

How to use this panel

When not to stop at size naming

Frequently asked questions

What is the difference between SI and IEC size families?

Why does a 1 TB drive look smaller in the OS?

What does the marketing gap peel show?

Are KB and KiB the same?

How is this different from the base converter?

Does this measure free disk space?

Bit vs byte?

Sources

What this number means

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