How is pipe volume calculated?

Volume = π × inner radius² × length. The calculator does this conversion using the inner diameter you enter, multiplied by the pipe length and quantity.

Inner diameter vs nominal pipe size — which should I use?

Use the actual inner diameter, not the nominal pipe size — they differ. For example, 4" nominal PVC has an actual inner diameter of about 4.026". The calculator's input is ID.

How are gallons calculated from cubic feet?

1 cubic foot = 7.48052 US gallons. The calculator applies this conversion to give you a US-gallon output alongside cubic feet and liters.

What if my pipe will be filled with water — how much will it weigh?

Water weighs 8.34 lb per US gallon. The calculator multiplies its gallon output by this constant to give the water weight in the pipe.

How many gallons in a 100 ft run of 2 inch pipe?

For 2" Schedule 40 PVC (actual ID 2.067"): volume = π × (2.067/24)² × 100 = 2.33 cu ft = 17.5 gallons. The calculator returns exact values for any pipe size and length.

Can I use this to size grout volume for piles or caissons?

Yes — the volume math is identical. The gallons and water-weight outputs aren't relevant for grout, but the cubic-feet and cubic-yard outputs convert directly to concrete or grout volume.

Pipe Volume Calculator

Calculate pipe internal volume, water capacity in gallons and liters.

Pipe Volume Calculator

Distance (ft)

Inner diameter

Number of pipes

Results

Total volume

Gallons

Liters

Water weight

Need Construction Business Software?

These calculators are even more powerful inside The Blocks. During takeoffs, material quantities are calculated automatically from your measurements — no manual entry needed.

Learn more about Digital Takeoffs, AI Estimates, and Cost Catalog.

Web access — desktop, tablet & mobile
AI-powered plan takeoffs
Manual markup tools
Cost estimating & budgets
Bid management & proposals
CRM & contact management

MonthlyAnnualSave 20%

Seats:

$119 per seat × 1$119/mo

Total

$119/mo

$1,428/yr

How to Use This Calculator

Formula

radius = (innerDiameter / 12) / 2volume = π × radius² × length × quantitygallons = volume(ft³) × 7.48052liters = volume(ft³) × 28.3168waterWeight = gallons × 8.34 lb/gal

Parameters

Inner Diameter: Pipe ID in inches, mm, or cm.
Quantity: Number of pipe runs.

Results

Volume: Total internal volume in cubic feet.
Gallons: Water capacity in US gallons.
Liters: Metric volume.
Water Weight: Weight if filled with water.

Example

100 ft of 4" PVC

4" inner diameter, 100 ft length, 1 pipe

radius = (4/12)/2 = 0.167 ftvolume = π × 0.167² × 100 = 8.7 cu ftgallons = 8.7 × 7.48 = 65.3 galwaterWeight = 65.3 × 8.34 = 544.5 lb

Common Use Cases

Plumbing system water capacity
Concrete filling of piles and caissons
Grout injection volume estimation
Fire suppression system sizing

Notes

Use inner diameter, not nominal pipe size (they differ).
Common 4" PVC has actual ID of 4.026".
PVC Schedule 40 actual IDs: 1/2" → 0.622", 3/4" → 0.824", 1" → 1.049", 1-1/2" → 1.610", 2" → 2.067", 3" → 3.068", 4" → 4.026", 6" → 6.065".
For grout / concrete fill rather than water: replace 8.34 lb/gal with concrete weight (~150 lb/ft³ = ~20 lb/gal).

Frequently Asked Questions

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Steel Weight Calculator

Free online steel weight and bar weight calculator — round bar, rebar, plate, pipe, angle, and square tube. Get weight per foot and total weight by shape and length.

Linear

Get in Touch

Zaur Zhanabekov

Sales

+1 347-962-1064 zaur@theblocks.app

Need Construction Business Software?

These calculators are even more powerful inside The Blocks. During takeoffs, material quantities are calculated automatically from your measurements — no manual entry needed.

Web access — desktop, tablet & mobile

AI-powered plan takeoffs

Manual markup tools

Cost estimating & budgets

Bid management & proposals

CRM & contact management

MonthlyAnnualSave 20%

Seats:

$119 per seat × 1$119/mo

Total

$119/mo

$1,428/yr

How to Use This Calculator

Formula

radius = (innerDiameter / 12) / 2volume = π × radius² × length × quantitygallons = volume(ft³) × 7.48052liters = volume(ft³) × 28.3168waterWeight = gallons × 8.34 lb/gal

Parameters

Inner Diameter: Pipe ID in inches, mm, or cm.
Quantity: Number of pipe runs.

Results

Volume: Total internal volume in cubic feet.
Gallons: Water capacity in US gallons.
Liters: Metric volume.
Water Weight: Weight if filled with water.

Example

100 ft of 4" PVC

4" inner diameter, 100 ft length, 1 pipe

radius = (4/12)/2 = 0.167 ftvolume = π × 0.167² × 100 = 8.7 cu ftgallons = 8.7 × 7.48 = 65.3 galwaterWeight = 65.3 × 8.34 = 544.5 lb

Common Use Cases

Plumbing system water capacity
Concrete filling of piles and caissons
Grout injection volume estimation
Fire suppression system sizing

Notes

Use inner diameter, not nominal pipe size (they differ).
Common 4" PVC has actual ID of 4.026".
PVC Schedule 40 actual IDs: 1/2" → 0.622", 3/4" → 0.824", 1" → 1.049", 1-1/2" → 1.610", 2" → 2.067", 3" → 3.068", 4" → 4.026", 6" → 6.065".
For grout / concrete fill rather than water: replace 8.34 lb/gal with concrete weight (~150 lb/ft³ = ~20 lb/gal).