At One Place

21 gal to fl oz

21 US gallons in US fluid ounces
21 gal = 2,688 fl oz
fl oz = gal × 128

21 US gallons is 2,688 US fluid ounces. To get there, multiply by 128.

Values either side

US gallons near 21, converted to US fluid ounces.
US gallons US fluid ounces
17 gal 2,176
18 gal 2,304
19 gal 2,432
20 gal 2,560
21 gal ← 2,688
22 gal 2,816
23 gal 2,944
24 gal 3,072
25 gal 3,200

How the conversion works

The relationship is fl oz = gal × 128. Both units measure volume, so the conversion is a fixed factor that never changes. The figure is exact rather than approximate: since the international yard and pound agreement of 1959, an inch is defined as exactly 25.4 millimetres and a pound as exactly 0.45359237 kilograms, and every other imperial and US customary unit here is derived from those two.

US gallon: US liquid gallon. The imperial gallon is about 20% larger.

Common questions

What is 21 gal in US fluid ounces?
21 gal is 2,688 fl oz.
How do you convert US gallons to US fluid ounces?
Multiply by 128.

Related pages

Sources

  1. Guide for the Use of the International System of Units (SP 811) — NIST (Public domain (US Government))
  2. The International System of Units (SI Brochure) — Bureau International des Poids et Mesures
  3. Calculated on this page — At One Place

How these figures are compiled and checked