Sandbag Calculator (How Many Sandbags Needed)

Posted by Jordan Hamasaki on Mar 17, 2026

Figure out the number of 14" x 26" polypropylene sandbags you need by inputting the length and height of the sandbag wall you'd like to build.

We recommend checking the FEMA’s Official Flood Map Service Center to find out the estimated amount of flooding and risk levels in your specific area.

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Using the sandbag calculator

Length of sandbag wall: Input the length of the wall.
Height of sandbag wall: Input the estimated height of the sandbag wall. We recommend you look at our sandbag wall guide.
Click "Calculate number of sandbags" to find out the number of 14" x 26" polypropylene sandbags you need.
1. Consider the time and people needed. For walls over 1 ft, we recommend a team of at least 3–5 people to manage the weight and filling process.

Safety note:
We recommend a maximum height of a sandbag wall at 1 ft. For safety and stability, walls higher than 1 foot must be built using a "pyramid" structure, as outlined in the U.S. Army Corps of Engineers (USACE) Sandbagging Guide.

Calculate the Number of 14"×26" Sandbags You Need

Figure out the number of 14" x 26" polypropylene sandbags you need by inputting the length and height of the sandbag wall you'd like to build.

L Length of Sandbag Wall

H Height of Sandbag Wall

⚠ Please enter valid values for both length and height.

Estimated Sandbags Required

🛍

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14" × 26" polypropylene sandbags

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Shop the exact 14" × 26" sandbags this calculator uses (free shipping to the continental U.S.).

Assumptions:

It takes an average of 600 sandbags to cover a 100 foot section, 1-foot high.
Sandbags are being laid length-wise end to end
The sandbag wall is 2-3 sandbags wide
Sandbag wall is rectangular

Disclaimer: provided that the assumptions listed above are taken into account, this calculator can only be used to provide a rough estimate of the number of sandbags required. Each case is different and requires your own personal judgment.

Dike Calculator (For High-Water Protection)

When floodwaters are expected to rise above 2 feet, a single-stack wall is no longer sufficient. You need to build a Dike, a pyramid-shaped barrier that uses a wide base to resist the intense pressure of deep or moving water.

The Dike Formula

The 3-to-1 Rule: For a dike to remain stable under pressure, the base must be three times wider than the height. These dimensions are based on engineering standards by Kenneth Hellevang, for sandbag dike construction to ensure the structure does not collapse under hydrostatic pressure.

SB = [ (3 × H) + (9 × H²) ] ÷ 2 × L

SB: Total Number of Sandbags
H: Desired Height of the dike
L: Total Length of the dike
W: Width of the dike base (always 3 × H)
AoS: Amount of sand needed, in cubic yards

How to Use the Calculator

Length (ft): Input the total distance you need to protect.
Height (ft): Input the target height.
Expert Tip: Always build your dike at least 1 foot higher than the predicted flood level to account for "freeboard" (waves and splashes).
Calculate: The tool will instantly provide the total number of 14" x 26" bags required to build a structural pyramid.

Note: Because each extra foot of height also forces the base to widen by 3 feet, material requirements grow with the square of height, which is why a 4-foot dike needs roughly 13× more bags than a 1-foot dike, not just 4×.

Dike Building Requirements

The 3-to-1 Rule: For a dike to remain stable under pressure, the base must be three times wider than the height. For example, a “4-foot-tall” dike requires a “12-foot-wide” base.
Estimated Bag Counts: Because of the wide base, dikes require significantly more material than standard walls:

1-Foot-High Dike: ~600 bags per 100 feet.
2-Foot-High Dike: ~2,100 bags per 100 feet.
3-Foot-High Dike: ~4,500 bags per 100 feet.
4-Foot-High Dike: ~7,800 bags per 100 feet.

Staggered Seams: Like a brick wall, always overlap your sandbags so the joints do not line up. This creates a "monolithic" structure that won't leak or shift under the weight of the water.
Seal the Deal: For a 100% watertight barrier, we recommend laying poly sheeting (plastic tarp) along the front of the dike before the final layer of bags is placed.

Bonding Trench (Required for Dikes Over 3 Feet)

If your dike will be taller than 3 feet, dig a bonding trench before placing any bags. The trench should be 6 inches deep and 24 inches wide, running the full length of your dike. This anchors the bottom layer of bags into the ground so the dike cannot slide forward under water pressure.

Sandbag Dike Calculator

Estimates sandbags needed for a 3×1 dike, where the base width is three times the height. Enter your dike dimensions below.

Formula (3×1 Dike) SB = [ (3 × H) + (9 × H²) ] ÷ 2 × L | Width = 3 × H

Units

(H) Height of Dike

(L) Length of Dike

⚠ Please enter a valid value for both height and length.

Your Dike Estimate

📦 Number of Sandbags (SB)

—

14" × 26" polypropylene sandbags

📐 Dike Width (W = 3×H)

—

ft wide at base

⛏ Sand Required (AoS)

—

cubic yards of sand

⏱ Labor Hours (LH)

—

person-hours to fill bags (at 12 bags/hr per person)

⚠ Bonding Trench Required Because your dike is taller than 3 ft, a bonding trench is recommended before placing bags. Dig a trench 6 inches deep and 24 inches wide along the full length of the dike (—). Total soil to excavate: — cubic yards.

How it works: This uses the U.S. Army Corps of Engineers 3×1 dike formula (Dr. Hellevang, NDSU). The base width is always 3× the height. Sand estimate assumes each 14"×26" bag holds ~0.4 cu ft when half-filled. Labor is estimated at 12 bags/person/hour (filling only, does not include transport or stacking time).
Results are estimates. Always apply personal judgment and consult local emergency management if needed.

Assumptions:

Each filled bag weighs 30-35 lb. A 100-foot wall (1-foot high) requires moving approximately 12 tons (23,000 lb) of sand.
A single-person can typically fill and place 12 bags per hour.
A sandbag dike is a pyramid-shaped sandbag barrier.

Disclaimer: Provided that the assumptions listed above are taken into account, this calculator can only be used to provide a rough estimate of the number of sandbags required. Each case is different and requires your own personal judgment.

Get Your 14" x 26" Polypropylene Sandbags Today!

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FAQ

How many sandbags do I need for a 100-foot flood wall?

You need 600 standard 14" x 26" sandbags to build a 100-foot wall that is 1 foot high. For walls higher than 1 foot, the number of bags increases significantly because safety standards require a wider pyramid base to prevent the structure from collapsing under water pressure.

How long will sandbags last?

Sandbags can last at least 3-6 months under direct sunlight and in high-heat places like California and Florida. They have 1600 hours of UV protection.

How tall is a sandbag? How big is a standard sandbag?

The most popular sizes of sandbag are 14 inches x 26 inches (36 cm x 66 cm) and 18 inches x 30 inches (46 cm x 76 cm). With the weight of the sand in the bag, sandbags with such dimensions and of this size can be used like bricks in building an interlocking sandbag wall.

How much do sandbags hold?

A standard 14" x 26" sandbag or 18" x 30" sandbag can hold up to 50 pounds of sand, but we recommend filling the bag to 30-35 lb of sand.
An overfilled sandbag (50-60 lb) will leave gaps which will allow water to seep through.

What is the typical volume and weight of a filled sandbag?

A sandbag should be filled 1/2 to 2/3 full and will weigh 35-40 lb. 30 sandbags would be about 1,000 lb and would be the maximum legal limit for a standard pickup truck.

Do sandbags help with traction? Where do you put sandbags in a truck bed?

To increase traction, sandbags should be placed over the rear axle on Rear-Wheel Drive (RWD) cars, right next to the wheel wells in a pickup truck.
However, adding weight to the back will not help with traction on All-Wheel Drive (AWD) or Front-Wheel Drive (FWD) vehicles.

How much help do I need to build a sandbag wall?

Building a sandbag wall is labor-intensive. For a standard 100-foot wall (1 foot tall), it takes approximately 50 to 60 man-hours to fill and place the 600 bags required. We recommend working in pairs: one person to hold the bag and one to shovel.

What do I do with sandbags after a flood?

Sandbags exposed to floodwaters may contain bacteria, sewage, or chemicals. Wear gloves when handling used bags. Do not reuse contaminated sand in playgrounds, sandboxes, or gardens. Contact your local waste management office for disposal instructions and drop-off locations, or follow these proper sandbag disposal and contamination safety guidelines.

Where can you get sandbags?

You can get 14" x 26" polypropylene sandbags (most popular) and 18" x 30" polypropylene sandbags on our website.

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