| Fluid ounces per hour (fl oz/h) | Fluid ounces per second (fl oz/s) |
|---|---|
| 1 Fluid ounce per hour | 0.000277777777778 fl oz/s |
| 2 Fluid ounces per hour | 0.000555555555556 fl oz/s |
| 3 Fluid ounces per hour | 0.000833333333333 fl oz/s |
| 4 Fluid ounces per hour | 0.00111111111111 fl oz/s |
| 5 Fluid ounces per hour | 0.00138888888889 fl oz/s |
| 10 Fluid ounces per hour | 0.00277777777778 fl oz/s |
| 20 Fluid ounces per hour | 0.00555555555556 fl oz/s |
| 25 Fluid ounces per hour | 0.00694444444444 fl oz/s |
| 50 Fluid ounces per hour | 0.0138888888889 fl oz/s |
| 100 Fluid ounces per hour | 0.0277777777778 fl oz/s |
| Reference | Fluid ounces per hour (fl oz/h) | Fluid ounces per second (fl oz/s) |
|---|---|---|
| A domestic shower | 19005.3 fl oz/h | 5.27926 fl oz/s |
| A kitchen tap | 21117 fl oz/h | 5.86585 fl oz/s |
| A garden hose | 31675.6 fl oz/h | 8.79877 fl oz/s |
| The Amazon river | 2.64808 × 1013 fl oz/h | 7.35577 × 109 fl oz/s |
The fluid ounce per hour is a unit of volumetric flow rate equal to one imperial fluid ounce passing a point every hour. Its symbol is fl oz/h. An imperial fluid ounce is 28.413 millilitres, so an hour at this rate delivers about two tablespoons — a rate slow enough that it is measured by what has collected, not by what is moving.
Slow feeding and slow dosing account for most of its use. A drip feeder on a bird cage, a wick humidifier, a fragrance diffuser and a slow-release fertiliser injector on a greenhouse line all move liquid at a few fluid ounces per hour, and the reservoir capacity divided by that rate gives the interval between refills.
Domestic appliances are described by it in older British literature. A paraffin heater consumes a few fluid ounces per hour, a wick lamp rather less, and an oil-filled stove was once sold with its consumption stated exactly this way so that a household could calculate how long a gallon would last through a winter evening.
Evaporation and leakage measurements fall here too. Water lost from an open tank, brake fluid seeping past a seal, or condensate collected from a small cooling coil are all quantified per hour, because that is the shortest period over which enough accumulates to measure in an ordinary graduated cylinder.
The unit's usefulness lies in matching the observation to the human timescale. Nobody watches a drip for a second; a technician checks a container after an hour, a shift or a night, and expressing the rate per hour lets the observed volume be divided by the elapsed hours with no further arithmetic.
For orientation, 160 fluid ounces make an imperial gallon, so one fluid ounce per hour fills a gallon in a little under a week. Thirty-five fluid ounces per hour is about a litre per hour, and sixty fluid ounces per hour is one fluid ounce per minute.
One fluid ounce per hour equals about 28.41 millilitres per hour, about 0.02841 litres per hour, or about 0.01667 fluid ounces per minute.
The fluid ounce per second is a unit of volumetric flow rate equal to one imperial fluid ounce passing a point every second. Its symbol is fl oz/s. The imperial fluid ounce is 28.413 millilitres, defined as one twentieth of an imperial pint, so this unit describes the flow of a steady pour rather than a plumbing system.
Its natural home is the bar and the kitchen. A pint glass filled in twelve seconds is being poured at about 1.7 fluid ounces per second, and a bartender free-pouring spirits counts seconds against a known rate to measure a shot without a jigger. Automatic dispensing guns on a bar are calibrated in exactly these terms so that a portion is repeatable across a busy evening.
Beverage plants use it for filling heads. A bottling line filling half-litre bottles at 200 bottles a minute must deliver about 59 fluid ounces per second in total, divided among however many heads the filler carries. Each head's individual rate determines the fill time, and the fill time determines how fast the carousel can turn.
The unit persists in British and Commonwealth food and drink specifications, where recipes, dispense rates and portion controls have been written in fluid ounces for generations. A soft-drink dispenser is set so that the syrup and the carbonated water arrive in a fixed ratio, and both rates are naturally quoted in fluid ounces per second.
A warning belongs here: the American fluid ounce is 29.574 millilitres, about four per cent larger than the imperial one, and the American pint holds sixteen of them against the imperial twenty. A flow rate quoted in fluid ounces per second therefore differs by four per cent between the two systems, and by twenty per cent when the same number of ounces is called a pint.
For a sense of scale, 35 fluid ounces per second is about a litre per second, and one fluid ounce per second fills a pint in twenty seconds and a gallon in a little under three minutes. It is the rate of a fast tap or a generous jug.
One fluid ounce per second equals about 28.41 millilitres per second, about 0.02841 litres per second, or about 1.734 cubic inches per second.