Hose Volume Calculator
Same volume in every unit
Fluid weight
Estimated fill / drain time
Your recent calculations (saved on this device)
| When | ID | Length | Result |
|---|
Hose is sized by inside diameter. A common 5/8" garden hose is preset — change it to yours.
How to use this calculator
- Choose the unit system — US, Imperial or metric — at the top of the calculator.
- Pick the pipe type and schedule, then the nominal size, and the real inside diameter loads for you. Or choose Custom and type any bore.
- Enter the pipe length. Open Advanced to set fill level, number of identical runs, a fittings allowance, the fluid, or a flow rate.
- Press Calculate to see the volume in every unit, plus fluid weight, cross-section area and fill or drain time.
- Copy, share or print the result. Recent calculations are saved on your own device so you can reopen them later.
Tip: not sure where to start? Use the Fill example data button to load a complete worked example — a 2-inch Schedule 40 line, 50 ft long, at 10 gal/min — then adjust the numbers to match your job.
Real-world uses, with numbers
Charging a radiant-heat loop
How much water sits in a 300 ft run of ½" PEX.
≈ 2.9 US galSizing a well pressure tank
Line-fill volume in 100 ft of 1" Schedule 40.
≈ 4.5 US galFlushing a main
Water to displace in 100 ft of 4" Schedule 40.
≈ 66 gal · 250 LWater weight on hangers
Load from a full 100 ft run of 2" pipe.
≈ 145 lb · 66 kgMetric heating fill
Charge volume for 50 m of 28 mm bore.
≈ 30.8 LFuel or oil line contents
Diesel held in 20 m of 50 mm bore.
≈ 39 L · 33 kgMore questions, answered
How do I convert between gallons, litres and cubic metres?
1 US gallon = 3.785 litres; 1 Imperial gallon = 4.546 litres; 1 m³ = 1,000 litres = 264.2 US gallons. The calculator shows all of them from a single entry, so you never convert by hand.
Does the pipe material change the volume?
Only through the bore. Two pipes with the same inside diameter hold the same volume whether they are steel, PVC, copper or PEX. Material and schedule matter because they set the real inside diameter for a given nominal size.
How much does the water inside a pipe weigh?
About 8.34 lb per US gallon, or 1 kg per litre. A full 100 ft run of 2" Schedule 40 holds roughly 17.4 gallons, about 145 lb. Set the fluid in Advanced for hot water, glycol, diesel or seawater.
What if I only know the outside diameter?
Switch the diameter to OD mode and enter the wall thickness; the tool subtracts two wall thicknesses to reach the bore. For a listed standard, just pick the size and the published inside diameter loads automatically.
Can I use it for a part-full or sloped drain?
Yes for a straight, round pipe: open Advanced and set the fill level below 100%, and the volume scales with it. Truly partial gravity flow in a sloped line follows a curved free surface, so treat the part-full figure as an approximation.
Notes and derived figures
- Volume scales with the square of the bore: doubling the inside diameter roughly quadruples the capacity, while doubling the length only doubles it.
- Per-foot and per-metre capacity are constant for a given bore, so any length is a single multiplication — handy for quick field estimates.
- Nominal size is a label. A "2-inch" Schedule 40 pipe has a 2.067-inch bore; using "2" overstates the volume by more than a third.
- Fill and drain time is volume divided by flow rate. Enter a flow rate in Advanced to turn any result into a charge, flush or drain time.
Hoses are sized by inside diameter
Unlike pipe, hose is labelled by its bore. A "5/8-inch garden hose" has a 5/8 in (0.625 in) inside diameter, so the volume calculation is direct — no schedule or wall lookup needed. Common household sizes are 1/2 in, 5/8 in and 3/4 in; the larger the bore, the more water the hose holds and the more it weighs when full.
How much water is in a garden hose?
A 50 ft, 5/8-inch hose holds about 0.8 US gallons — roughly 3 litres, weighing about 6.7 lb. Step up to a 100 ft, 3/4-inch hose and it holds about 2.3 gallons, close to 19 lb of water. That is why a long, full hose is heavy to drag and worth draining before you coil it. Enter your own length and bore above for the exact figures.
Handy things to know from hose volume
- Wasted water — the volume you flush before hot or clean water arrives.
- Weight when full — how heavy the hose is to move or hang.
- Drain and blow-out — what to clear before winter storage.
- Chemical and fertiliser mixing — line contents affect dosing through a hose-end feeder.
Drain and fill time for a hose
Enter a flow rate and the tool estimates how long the hose takes to fill or drain. For a trickle drain, that can be several minutes even on a short hose; at full tap flow, a hose fills in seconds. Knowing the volume turns "wait until it runs clear" into a number you can plan around.
Accuracy notes for hose
Hose bore can vary a little between products, and kinks or fittings reduce the effective volume slightly. For everyday use the nominal inside diameter is close enough. If you have measured the actual bore — or you are working with lay-flat or reinforced hose whose stated size differs from its bore — enter the measured inside diameter for the best result.
Reading and trusting your result
The result above answers most questions; this note covers how to interpret it and its limits.
What the number actually means
The headline value is the internal capacity of a round, uniform pipe running full — the fluid the bore can hold along the length you entered. Every other unit on the panel is the same physical quantity re-expressed, so you can quote whichever your paperwork needs without recalculating.
The full-pipe assumption
By default the figure assumes the pipe is completely full and perfectly cylindrical. For gravity drains and vented lines that run part full, set a fill level below 100% and the result scales with it. Bends, valves and fittings add a little capacity the straight-length model does not see — use the fittings allowance to approximate them.
Capacity reference tables & a worked example
Concrete numbers for this page, calculated the same way the tool above does — use them as a quick check or a lookup.
Water in a 3/4" hose by length
Hose is sized by its bore, not a schedule, so the maths is direct. A common 3/4" garden hose (0.75 in inside) holds surprisingly little — here is how the contents build up as the hose gets longer.
| Length (ft) | Volume (US gal) | Per foot |
|---|---|---|
| 25 ft | 0.57 | 0.0229 |
| 50 ft | 1.15 | 0.0229 |
| 75 ft | 1.72 | 0.0229 |
| 100 ft | 2.29 | 0.0229 |
| 150 ft | 3.44 | 0.0229 |
| 200 ft | 4.59 | 0.0229 |
Capacity by hose bore
How much a 50 ft length holds across everyday hose sizes, in US gal. Doubling the inside diameter roughly quadruples the water sitting in the line — worth knowing before you drain or dose one.
| Inside diameter | Per foot (US gal) | Volume in 50 ft (US gal) |
|---|---|---|
| 1/4" | 0.0025 | 0.13 |
| 3/8" | 0.0057 | 0.29 |
| 1/2" | 0.0102 | 0.51 |
| 5/8" | 0.0159 | 0.80 |
| 3/4" | 0.0229 | 1.15 |
| 1" | 0.0408 | 2.04 |
Worked example
- Take a 5/8" hose, inside diameter 0.625 in, radius 0.3125 in.
- Area = π × 0.3125² = 0.3068 in².
- Over 100 ft (1,200 in): 0.3068 × 1,200 = 368.2 in³.
- That is 1.59 US gal of water held in a full 100 ft of 5/8" hose.
Frequently asked questions
How much water does a garden hose hold?
A 50 ft, 5/8-inch hose holds about 0.8 US gallons (3 litres). A 100 ft, 3/4-inch hose holds about 2.3 gallons. Enter your length and bore above for an exact figure.
How do I calculate hose volume?
Hose is sized by its inside diameter, so use V = π × (ID/2)² × L directly. Enter the bore and length above.
How much does a full hose weigh?
Add the water weight (about 8.34 lb per US gallon) to the empty hose weight. The calculator shows the water weight for you.
Does hose diameter mean the inside or outside?
Hose sizes refer to the inside diameter (the bore), unlike pipe. Use that value directly.
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What people say
Used the litres-per-metre figures to size a glycol charge for a radiant job. Numbers matched the datasheet.
Switches between US and metric without losing the pipe. Small thing, big time-saver.
Would love more HDPE DIPS sizes, otherwise excellent.