Cubic feet per second (ft³/s) to Cubic feet per hour (ft³/h) conversion

Understanding Cubic feet per second to Cubic feet per hour Conversion

Cubic feet per second ($ft^3/s$) and cubic feet per hour ($ft^3/h$) are both units of volume flow rate, meaning they describe how much volume passes a point over time. The difference is the time basis: one uses seconds, while the other uses hours.

Converting between these units is useful when comparing flow data from different instruments, engineering documents, utility specifications, or process reports. A value expressed per second may be more convenient for fast-moving systems, while per hour is often easier to read for longer-duration planning and reporting.

Conversion Formula

The verified relationship between these units is:

$$1\ ft^3/s = 3600\ ft^3/h$$

So, to convert from cubic feet per second to cubic feet per hour:

$$ft^3/h = ft^3/s \times 3600$$

The reverse relationship is:

$$1\ ft^3/h = 0.0002777777777778\ ft^3/s$$

Which can also be written as:

$$ft^3/s = ft^3/h \times 0.0002777777777778$$

Step-by-Step Example

Suppose a ventilation or air-handling system has a flow rate of $2.75\ ft^3/s$.

Write the formula:

$$ft^3/h = ft^3/s \times 3600$$

Substitute the given value:

$$ft^3/h = 2.75 \times 3600$$

Calculate:

$$ft^3/h = 9900$$

So, a flow rate of $2.75\ ft^3/s$ is equal to $9900\ ft^3/h$.

Real-World Examples

• A small industrial exhaust fan moving $1.5\ ft^3/s$ of air would be rated as $5400\ ft^3/h$ in hourly terms.
• A ducted ventilation line carrying $8\ ft^3/s$ corresponds to $28800\ ft^3/h$, which can be useful in building airflow summaries.
• A compressed air or gas process stream measured at $0.65\ ft^3/s$ equals $2340\ ft^3/h$ for hourly production reporting.
• A larger process flow of $12.2\ ft^3/s$ converts to $43920\ ft^3/h$, a scale that may appear in plant utility balance sheets.

Interesting Facts

• Cubic foot is a unit of volume in the U.S. customary and imperial measurement context, and volume flow rate units such as cubic feet per second are commonly used in engineering, fluid handling, and ventilation applications. Source: Wikipedia – Cubic foot
• The conversion factor between $ft^3/s$ and $ft^3/h$ comes directly from the time relationship between seconds and hours: one hour contains 3600 seconds, so a per-second flow becomes 3600 times larger when expressed per hour. Source: NIST – SI units and time definitions

Summary

Cubic feet per second and cubic feet per hour describe the same kind of quantity: volumetric flow rate. The key difference is only the time interval used in the denominator.

Using the verified conversion:

$$1\ ft^3/s = 3600\ ft^3/h$$

the conversion from $ft^3/s$ to $ft^3/h$ is performed by multiplying by $3600$.

For reverse conversion, the verified relationship is:

$$1\ ft^3/h = 0.0002777777777778\ ft^3/s$$

This makes it straightforward to move between short-interval flow measurements and hourly reporting values in engineering, HVAC, utility, and process settings.

How to Convert Cubic feet per second to Cubic feet per hour

To convert Cubic feet per second to Cubic feet per hour, use the fact that one hour contains 3600 seconds. That means a flow rate in ft3/s is multiplied by 3600 to get ft3/h.

1. Write the conversion factor:
   Use the known relationship between seconds and hours:

   $$1 \,\text{ft}^3/\text{s} = 3600 \,\text{ft}^3/\text{h}$$

2. Set up the conversion:
   Start with the given value and multiply by the conversion factor:

   $$25 \,\text{ft}^3/\text{s} \times \frac{3600 \,\text{ft}^3/\text{h}}{1 \,\text{ft}^3/\text{s}}$$

3. Cancel the original unit:
   The $\text{ft}^3/\text{s}$ unit cancels, leaving only $\text{ft}^3/\text{h}$:

   $$25 \times 3600 = 90000$$

4. Result:

   $$25 \,\text{ft}^3/\text{s} = 90000 \,\text{ft}^3/\text{h}$$

A quick way to remember this conversion is that going from per second to per hour always means multiplying by $3600$. If you go the other direction, divide by $3600$ instead.

What is the formula to convert Cubic feet per second to Cubic feet per hour?

Use the verified factor: $1\ \text{ft}^3/\text{s} = 3600\ \text{ft}^3/\text{h}$.
The formula is $\text{ft}^3/\text{h} = \text{ft}^3/\text{s} \times 3600$.

How many Cubic feet per hour are in 1 Cubic foot per second?

There are $3600\ \text{ft}^3/\text{h}$ in $1\ \text{ft}^3/\text{s}$.
This follows directly from the verified conversion factor.

Why do you multiply by 3600 when converting ft3/s to ft3/h?

You multiply by $3600$ because the conversion from seconds to hours uses the verified relationship $1\ \text{ft}^3/\text{s} = 3600\ \text{ft}^3/\text{h}$.
This lets you express the same flow rate over a one-hour period instead of a one-second period.

Where is converting Cubic feet per second to Cubic feet per hour used in real life?

This conversion is useful in HVAC, water flow monitoring, industrial ventilation, and pipeline systems.
For example, a flow measured in $\text{ft}^3/\text{s}$ may be converted to $\text{ft}^3/\text{h}$ for hourly reporting, equipment sizing, or system capacity comparisons.

Can I convert decimal values from ft3/s to ft3/h?

Yes, decimal values convert the same way using $\text{ft}^3/\text{h} = \text{ft}^3/\text{s} \times 3600$.
For instance, if a flow rate is given as a decimal in $\text{ft}^3/\text{s}$, multiply that value by $3600$ to get $\text{ft}^3/\text{h}$.

Is the conversion factor from ft3/s to ft3/h always the same?

Yes, the factor is always $3600$ for converting Cubic feet per second to Cubic feet per hour.
Because both units measure volumetric flow rate, the conversion does not change with the material being measured.