1" pipe 50 ft
Input
1" diameter · 50 ft lengthOutput
≈ 2.04 galπ×0.5²×600 in ÷ 231 ≈ 2.04 gal.
Total drop = horizontal run (ft) × slope (in/ft). IPC minimum is 1/4 in/ft for pipes 3 in and smaller.
Use the calculator form above with your measurements. Results update instantly in your browser — no data is sent to a server.
Total drop = horizontal run (ft) × slope (in/ft). IPC minimum is 1/4 in/ft for pipes 3 in and smaller.
Formula
See calculator inputs and results panel for step-by-step math.Select imperial/metric, tank vs tankless, or bedrooms vs occupants as shown.
Type pipe dimensions, fixture counts, household size, or simultaneous fixture use.
Use slope or run presets for common drain grades and PEX runs.
Use gallons, pipe size, GPM, or tank capacity in the results panel.
Copy results or share a link with your plumber or inspector.
Use Pipe Sizing or Hot Water Flow calculators for a full plumbing takeoff.
Input
1" diameter · 50 ft lengthOutput
≈ 2.04 galπ×0.5²×600 in ÷ 231 ≈ 2.04 gal.
Input
30 ft run · 1/4" / ftOutput
7.5" drop30 × 0.25 = 7.5 inches.
Common real-world scenarios where this tool saves time.
100 ft of 3/4" PEX with 10% buffer → order ~110 ft in two 100 ft coils.
40 ft run at 1/4" / ft → 10" total drop for proper gravity flow.
2 showers + 1 sink at 70°F rise → ~5 GPM peak, ~175,000 BTU/hr class heater.
3-bedroom home → ~6 occupants → 1,000–1,250 gal tank typical starting point.
Step-by-step chains that connect related tools for common tasks.
From pipe volume to heater and pump sizing.
| Slope | Percent grade | Typical use |
|---|---|---|
| 1/8" / ft | 1.04% | Large drain pipe |
| 1/4" / ft | 2.08% | IPC min ≤3" |
| 1/2" / ft | 4.17% | Steep runs |
Measure ID or nominal size per manufacturer spec for volume and sizing.
BTU need scales with °F rise — colder groundwater needs more capacity.
Tank water heaters need adequate first-hour rating (FHR), not just storage volume.
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About 0.04 gallons per foot of 1-inch ID pipe — use the Pipe Volume Calculator for exact gallons.
IPC commonly requires 1/4 inch per foot for pipes 3 inches and smaller; larger pipes may use 1/8 inch per foot.
Add GPM of fixtures running at once, then ensure BTU/hr ≥ GPM × temperature rise × 500.
Water Supply Fixture Units and Drain Fixture Units — standardized loads used to size supply and drain pipes.
Measure total run, add 10% for fittings and waste, then divide by coil length and round up.
Often 1,000 gal minimum for small homes; size up with bedrooms/occupants and daily wastewater flow.
Residential basements often need 20–40 GPM depending on floor area and discharge head height.
No — it is a planning estimator. Licensed plumbers and inspectors should verify final designs.
Drain run and slope values are processed locally — no drain-slope calculator data is sent to EverydayTools servers.
Estimates only — not professional plumbing advice. Verify with a licensed plumber and local code before installation.
Part of Calculator Tools
More free tools for the same workflow.
Free French drain calculator: trench length, width, and fill depth → cubic yards and bags of drain rock. Foundation and downspout presets, 12–24 in depth guide, order buffer. Imperial or metric. Runs locally in your browser.
Free water heater calculator: Size a tank or tankless water heater from household occupants and peak fixture use — tank gallons or tankless GPM and BT Runs locally in your browser — no signup.
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Reviewed on 2026-06-28.
IPC minimum is 1/4 in/ft for pipes ≤3 in