When the Console Says GiB and the Price Sheet Says GB
Provision a block volume and the console asks for a size in GiB. Look at the instance type and its memory is quoted in GiB. Run free -h on the box and the totals come back in Gi. Then open the pricing page or the monthly usage report and the line item is denominated in GB. Same resource, two labels, and the two labels are not the same size — which is exactly the kind of ambiguity that turns a capacity review into an argument.
This page is the translation layer. Type the GiB figure your console shows and read the decimal gigabyte equivalent, so that when you compare a quote, fill in a spreadsheet or reconcile a usage line, you know precisely which quantity you are holding.
GB = GiB × 1.073741824. A 500 GiB volume is 500 × 1.073741824 = 536.870912 GB of decimal capacity.Consoles Think in Powers of Two
Billing Documents Say GB
A 7.4% Gap Is Not Noise
Converting a Provisioned Size Before You Price It
Take the figure the console or shell reports
Volume size from the storage page, memory from the instance description, or the Gi totals from free -h and lsblk. Type it into the GiB field; spaces and thousands separators are ignored and a decimal comma works as well as a dot.
Read the decimal gigabyte equivalent
The second field updates as you type, to eight decimal places where the value needs them, so an exact figure is available when you are reconciling against a usage export rather than eyeballing a dashboard.
Paste it into the ticket or the sheet
The copy button on each field yields the bare number with no unit suffix, which is what a cost model, a capacity spreadsheet or a quota-increase form expects in its numeric column.
Reverse it for a vendor-quoted number
When a supplier hands you a decimal GB figure and you need to know what to type into a console that expects GiB, use the swap button or simply type into the gigabyte field — both fields drive the conversion.
The unit menus on both sides are searchable and list the whole storage ladder, so the same two fields also cover TiB against TB when you move up from a single volume to a fleet total.
Cloud Volume and Instance Memory Sizes in Both Units
The sizes below are the ones that actually appear in consoles: default boot volumes, standard instance memory tiers and the round GiB numbers architects keep reaching for. The right-hand column is what the same capacity is in strict decimal gigabytes.
| Provisioned size | Gibibytes | Decimal gigabytes |
|---|---|---|
| Small instance memory | 8 GiB | 8.589934592 GB |
| Mid-tier instance memory | 16 GiB | 17.179869184 GB |
| Memory-optimised instance | 32 GiB | 34.359738368 GB |
| Common default boot volume | 100 GiB | 107.3741824 GB |
| Application data volume | 500 GiB | 536.870912 GB |
| One tebibyte of block storage | 1 024 GiB | 1 099.511627776 GB |
Notice the last row: the volume a console calls 1 TiB is 1 099.51 GB in decimal terms, not 1 000. If a capacity plan mixes a console figure with a decimal figure anywhere in the chain, that discrepancy propagates all the way to the forecast.
Normalise Two Providers to One Unit
When one platform quotes GiB and another quotes GB, put both through the same field before comparing prices per unit. It takes seconds and removes the single most common apples-to-oranges error in a cloud comparison.
Exact Figures for Reconciliation
Results carry up to eight decimals with thousands spaced for readability, which is enough precision to match a usage export line rather than approximate it.
Fast Enough for a Live Review
Conversion happens in the browser as you type, so you can run figures during a capacity meeting without waiting on a request or losing your place in the console tab next door.
Questions From Cloud Capacity Reviews
Why do cloud consoles size volumes in GiB at all?
Because the underlying resources are binary. Block devices are addressed in sectors and allocation units that are powers of two, and physical memory is organised in pages of the same shape. Expressing those quantities in gibibytes keeps the console honest about what the platform can actually hand out. Decimal gigabytes are a human and commercial convention layered on top, which is why the marketing and billing surfaces drift toward GB while the technical surfaces stay on GiB.
If I provision 100 GiB, is my bill for 100 units or 107.37?
Usually 100. The major platforms bill block storage per provisioned unit per month, and the “GB-month” on the invoice is their name for the same unit you provisioned in the console — provision 100, get billed for 100, whether or not you write a single byte to it. The decimal conversion matters not for that line item but for everything you build around it: comparing a per-unit price against a vendor whose GB really is decimal, or checking whether the capacity you were promised in a contract matches the capacity the console can create. Confirm your provider's convention in its own documentation rather than inferring it from the letters.
Why does the memory in free -h fall short of the instance's advertised GiB?
Two effects stack. First, the tool reports what the kernel has available after firmware, the hypervisor and reserved regions have taken their share, so a 16 GiB instance typically shows a little under 16 Gi of total memory. Second, free -h prints in binary units by default, so those numbers are directly comparable to the instance specification — but not to any figure elsewhere in your stack that is written in decimal GB. Use free --si if you want the decimal view, and never compare the two outputs to each other without converting.
Which unit belongs in a quota-increase request?
The one the quota itself is named in, and it is worth checking rather than guessing — some platforms have quota identifiers with GB in the name that are counted in the GiB you provision. Write the request against the quota's own unit, state your target explicitly, and add the converted figure in parentheses so the reviewer cannot misread it. It also pays to remember that some resources consume quota at more than face value: replicated or regional volumes can draw double their nominal size because the capacity exists in two zones.
How do I compare two providers when one quotes GiB and the other GB?
Convert both to a single unit before dividing by price, and record in the comparison sheet which unit you standardised on. A provider quoting a rate per decimal GB looks about 7% cheaper than an identical rate per GiB purely because of the unit, and that is enough to flip a decision on a large commitment. Then repeat the exercise for the sizes themselves: two “1 TB” offerings can differ by nearly a hundred gigabytes depending on which convention each vendor used to write the number.
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