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US cups to US fluid ounces converter

Read a quantity in US cup, then express the same volume in US fl oz. The units are defined below to avoid mixing similarly named standards.

≈ 8 US fl oz

Up to 12 significant digits are displayed; floating-point results are approximate. No value is saved.

Direct example

1 US cup ≈ 8 US fl oz.

Formula and calculation

US fl oz = US cup × 8

Substituting 1 US cup gives approximately 8 US fl oz. Definitions use the constants above; arithmetic uses browser floating point and displays at most 12 significant digits. The rounded table is not an instrument calibration or certified measurement.

Which units does this page use?

US cups: US customary cup: 8 US fluid ounces; not the 240 mL nutrition-label or 250 mL metric cup.

US fluid ounces: US liquid fluid ounce, not the imperial fluid ounce or mass ounce.

When this direction is useful

Start here when your source record uses US cup for US customary recipe volumes, but the receiving specification is expressed in US fl oz for US drink and liquid product volumes. Enter the original quantity rather than reusing a previously rounded result. If your source uses US fl oz, use the reverse converter instead.

Conversion table

Approximate displayed values, with the same definitions as the converter
US cups (US cup)US fluid ounces (US fl oz)
00
18
540
1080
100800

Limits and interpretation

These are non-negative physical quantities; negative inputs are rejected. Converting a unit changes neither the measured object nor the original precision. Use a decimal dot; grouping commas are not accepted. No external rates, live data or account are involved.

Frequently asked questions

Can I convert the other way?

Yes. Convert US fluid ounces to US cups with the inverse equation. Rounding a result before converting it back can introduce a small difference.

Are these the same as every similarly named unit?

No. Check the two definitions above. International length, avoirdupois mass, US customary liquid measures and temperature readings are explicitly distinguished; an ambiguous label on a source document must be resolved first.

Where do the conversion definitions come from?

They use SI and defined customary conversion relationships. See the NIST Guide for the Use of SI. Output formatting is this tool's display policy, not extra measurement accuracy.

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