Hose Length Calculator
Estimate routed hose length from measured distance, bends, slack, fittings, reel wraps, drip loops, diameter, and a water-style pressure loss check.
Hose length result
Breakdown
| Inside diameter | Typical water flow | Good velocity range | Length note |
|---|---|---|---|
| 3/8 in / 10 mm | 1-4 gpm | 3-10 ft/s | Short whips and pressure washers |
| 5/8 in / 16 mm | 5-12 gpm | 3-8 ft/s | Common garden and utility runs |
| 3/4 in / 19 mm | 8-18 gpm | 3-9 ft/s | Washdown and shop service |
| 1 in / 25 mm | 15-35 gpm | 4-10 ft/s | Transfer and light discharge |
| 1-1/2 in / 38 mm | 40-100 gpm | 4-12 ft/s | High-flow discharge hose |
| Allowance item | Common input | Why it matters | Field to adjust |
|---|---|---|---|
| Wide bend | 90 degrees at 4-8 in | Arc length replaces a sharp corner | Bends, angle, radius |
| Quick coupler | 3-6 in each | Adds tail length and handling room | Fittings and fitting allowance |
| Drip loop | 1-2 ft drop | Keeps fluid away from equipment | Drip loops and loop drop |
| Service reel | 1-4 wraps | Leaves hose on the drum at full pull | Reel wraps and reel diameter |
| Movement slack | 8-15 percent | Prevents pull-out during use | Slack percentage |
| Hose type | Hazen C used | Routing character | Practical note |
|---|---|---|---|
| Smooth PVC | 145 | Low friction | Good for long water runs |
| Rubber water | 130 | General purpose | Use moderate slack and bend radius |
| Layflat discharge | 135 | Wide bends | Allow for flattening and movement |
| Corrugated suction | 105 | Higher friction | Keep it short and avoid tight bends |
| Hydraulic return | 120 | Oil service guide | Use manufacturer data for final sizing |
When calculating the length of a hose, it is necessary to ensure that the length is the correct length to reach the necessary connection. If the hose is too short, it will not be able to reach the necessary tools or outlets. In addition, once the clamp on the hose are tightened, it isnt possible to fix a short hose.
Many people will use a tape measure to determine the length of the hose that will be necessary. However, the tape measure may not reflect the length of the hose that will be necessary due to the potential for vertical rise or bends in the equipment. Therefore, it is necessary to account for the actual path that the hose will travel, which will include more length than the straight-line distance between the two outlet.
How to Measure and Calculate Hose Length
To use the hose length calculator, there are several specific inputs that must be provided. The length of the hose along the actual route, the vertical change in length, and any additional segment along routed walls or racks must be entered. These determine the base run of the hose.
However, the base run is not the length of the hose that will be purchased. To account for the length that is swallowed up by the fittings, the length of the arc of the bends along the hose, and the length of the wraps on the hose reel, you will add extra length to the base run. In addition to the extra length of the hose, it is necessary to provide a percentage for the slack that will be provided in the hose.
A percentage will allow for longer hoses to have more slack, as additional length will be needed for the hose to move. For instance, an eight or ten percent slack allowance will allow for the hose to move due to vibration. In applications involving hydraulic return lines that move in a variety of direction, a fifteen percent slack allowance is often used.
This percentage will be applied to the length of the base run and the extra length provided for the bends in the hose. Bend radius is a consideration in the hose length calculation. If the bend radius is set to a tight radius, it will shorten the length of the hose that is use to perform the task.
However, tight bends can cause kinking of the hose and loss of pressure within that hose. Therefore, it is necessary to enter the number of bends and the bend radius that will be used in the hose into the calculator. The calculator will provide a warning if the bend radius that is entered is less than the recommended radius for that type of hose.
While some hoses can tolerate more bends than others, the hose manufacturer can provide this information. Another consideration within the calculator is the concept of pressure loss. Length and diameter play a major role in the friction in the hose that can reduce the pressure of the fluid.
Smaller diameter and longer lengths will have a greater effect on the loss of pressure within the hose. The percentage of pressure loss is calculated using the Hazen-Williams equation. This equation is used for estimating the pressure loss of water and water-based fluids.
Based off the percentage of pressure loss that is calculated, it is possible to determine if the diameter of the hose is providing sufficient pressure to reach the end of the hose. If the percentage is too high, you can increase the diameter of the hose to reduce the loss of pressure. Reel wraps and drip loops are additional features of the calculator.
Reel wraps calculate the amount of hose that will remain on the hose reel when it is extended to perform its tasks. If the hose contains three full wraps on the reel, for instance, the hose will remain on the reel even when the hose is fully extend. This extra length of hose can help protect the fitting on the hose reel hub.
Additionally, drip loop will allow water to drip away from sensitive electrical enclosures. Though the length of these two features is relatively small, they can help ensure that the hose will not need to be modified once it is installed. The material of the hose will impact the calculation of the pressure loss in the hose.
Smooth PVC will have a higher coefficient than rubber hose, leading to a higher rate of pressure loss. Corrugated suction hoses will have a different coefficient that will result in an increased rate of pressure loss compared to smooth PVC hoses. These coefficient are automatically entered into the calculator when the user selects the type of hose to be used.
The reference tables provide information regarding hose diameters and the flow of fluids through those hoses. These are provided as ranges, as each specific system can differ in terms of the temperature and the fluid that passes through those hoses. For instance, a 5/8-inch garden hose can handle eight gallon per minute of water.
However, for a 5/8-inch hose that must move longer distance for air drop applications, the diameter would have to be increased to ensure that fluid is not forced through the bends in the hose. The velocity of the fluid is checked to ensure it falls within the range of most hoses. An additional step that can be taken to ensure accuracy of the length of the hose that will be purchased is to measure the actual length of the route after the major pieces of equipment have been installed.
This will allow the installer to account for any door or brackets that may require the hose to make bends. By entering each of these measurement into the calculator, the length of the hose can be accurately calculated. Finally, another consideration is the rounding of the length of the hose that is calculated by the calculator.
Since it is not likely that the length of the hose will be cut to the calculated length, the length should of be rounded up by five or ten percent. This provides for the hose to be trimmed to the proper length and for clamp to be placed on the hose. However, it is necessary to remember that the calculation of the length of the hose is only one part of the task of selecting the appropriate hose for the service that will be performed.
The working pressure of the hose, the temperature at which it will be used, the compatibility with the fluid that will pass through the hose, and the minimum bend radius for that specific hose must also be determined from the manufacturer’s specification. Ensuring that the length of the hose is correct the first time will save both the installer and the customer from the purchase of additional hose or extensions to the hoses that are already installed.
