How many sandbags do I need for a flood barrier?

The Army Corps of Engineers pyramid table gives bags per 100 ft of barrier: 600 at 1 ft high, 2,100 at 2 ft, 4,500 at 3 ft and 7,800 at 4 ft. A 100 ft barrier 2 ft high is 2,100 bags, 2,205 with 5% extra for split bags. Taller walls need many more bags for each foot because the base grows with the height. These are the Portland District's rows; other Corps districts print slightly different ones (800 bags at 1 ft, 2,000 at 2 ft), so the count is an estimate.

How much sand do I need for sandbags?

Bags × the sand in each. A bag filled half to two-thirds full holds about 30 to 40 lb of damp sand. 2,205 bags of 40 lb is 44.10 tons, 32.70 cu yd at 1.35 tons per cu yd; at 30 lb a bag the same wall is 33.10 tons. NDSU Extension puts a cubic yard of sand at roughly 75 bags of 40 lb or 100 bags of 30 lb, using a denser 110 lb per cu ft, so its volumes come out a little lower than this calculator’s. Weights are for damp sand; dry sand is lighter, wet sand heavier.

Why is the base three times the height?

The Corps builds a sandbag levee as a pyramid with a base about three times as wide as it is tall, so the bags lean on each other and the wall does not roll or slide. A 2 ft wall is 6 ft wide at the base and a 3 ft wall 9 ft. That width is why a tall wall uses so many bags. Some Corps pamphlets size the width from the bags themselves (3 bags wide is about 2.5 ft), so leave some extra room.

How high can a sandbag wall be?

Three feet is the preferred limit and 5 ft the practical limit in the Corps’ St. Paul District guidance; above that, use other means or an engineer. This calculator counts bags up to 4 ft (the Corps table stops there), shows a note above 3 ft, and counts none above 4 ft. Build the wall at least 1 ft higher than the water you expect. A 3 ft barrier 50 ft long needs 2,363 bags and 47.30 tons of sand.

When is a single row of sandbags enough?

The Corps gives one single-row figure: 300 bags per 100 ft for a wall 1 ft high, one bag wide with the bags lying lengthwise. That is 300 bags for 100 ft, against 600 for a 1 ft pyramid. A single row is narrow and easily pushed over, so use it for short, low diversions where the water is shallow and slow; the calculator allows it only up to 1 ft.

How long does it take to fill sandbags?

A municipal planning rule is 20 bags per person-hour to fill them, which puts 2,205 bags at about 111 person-hours; other guides quote 40 to 60 bags per person-hour with a good crew, a funnel and a stacker. This is a rule of thumb and not a Corps figure; hauling and placing take extra time, and heavy bags slow people down. Two people filling and a third tying or stacking is a common team.

How full should I fill a sandbag?

About half to two-thirds full, so the bag can be laid flat and the top folded under, which makes it lie tight against its neighbours. A bag filled to the top is round and does not stack. Untied bags are the Corps’ usual choice for a wall; bags that will be moved or thrown are tied. Filled to this level a bag weighs about 30 to 40 lb: a weight one person can lift with good form, not more.

How many sandbags do I need for a doorway?

A 3 ft wide door 1 to 1.5 ft high is a short run: 10 ft of 1.5 ft barrier, a little more than the door width on each side, is 142 bags with 5% extra. Short, low barriers like this slow shallow water but do not stop it, and they should be sealed with plastic.

Do sandbags stop a flood?

They slow and divert shallow water for a while; they do not make a watertight seal, and they are not an engineered flood wall. Laying heavy plastic sheeting over the flood side of the wall and weighting its toe cuts seepage a lot. Water will still come through and under, so plan a sump pump, and move valuables and anything electrical up and out. Follow your local emergency management office, which may supply bags and sand.

Sandbag Calculator: How Many Sandbags and How Much Sand Do I Need?

A sandbag barrier 100 ft long and 2 ft high, built as the Army Corps of Engineers pyramid (base 3 times the height, so 6 ft wide), needs 2,205 bags: the Corps table gives 2,100 bags per 100 ft at 2 ft, plus 5% for split or lost bags. At 40 lb of sand a bag that is 44.10 tons of sand, about 32.70 cu yd, and about 111 person-hours to fill them (a planning rule, not a Corps figure). Enter the length and height (1 to 3 ft is the preferred range) to get your own count. Sandbags slow and divert shallow water; they do not seal, so read the safety notes below.

Figures based on the sources listed belowUpdated 2026-10-15How we calculate

Barrier length

Barrier height

Extra bags

Standard: split or lost bags (5%)Generous: a spare supply (10%)Exact (0%)Custom

Wall typeThe pyramid is the Corps’ standard levee. The single-row figure exists only for walls up to 1 ft high, and a single row is easily pushed over: use it for a short diversion, not for holding back moving water.

Sand per bagA bag filled half to two-thirds full holds about 30 to 40 lb of damp sand. The bag count does not change; the sand does.

Price per bag (optional)

Buy 2,205 bags

100 linear ft + 5% waste = 105 linear ft

Pyramid base width (3 × height): 6 ft, plus room for the plastic sheet
Sand by weight: 44.1 tons, 40 lb a bag
Sand by volume (approximate): 32.67 cu yd, at about 1.35 tons per cu yd
Filling labor (planning guidance): 111 person-hours, at 20 bags per person-hour

How this number is calculated

100 linear ft + 5% waste = 105 linear ft ÷ 0.0476 linear ft per bag = 2,205 bags

Shopping list

Empty sandbags, polypropylene (14 × 26 in)
Heavy-duty plastic sheeting (6 mil, for the flood side)
Sandbag filling funnel
Square-point shovel
Work gloves
Back support belt

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Sandbags per 100 ft of barrier by height

Worked by this calculator for a pyramid with no extra bags and 40 lb of sand a bag; bags per 100 ft are the Corps table’s rows.
Height	Base width	Bags	Sand (tons)	Sand (cu yd)	Fill (person-hours)
1 ft	3 ft	600	12	8.90	30
2 ft	6 ft	2,100	42	31.10	105
3 ft	9 ft	4,500	90	66.70	225

Bags and sand by barrier length at 2 ft high

A 2 ft pyramid with 5% extra bags and 40 lb of sand a bag, worked by this calculator.
Length	Bags	Sand (tons)	Sand (cu yd)	Fill (person-hours)
10 ft	221	4.40	3.30	12
25 ft	552	11	8.20	28
50 ft	1,103	22.10	16.30	56
100 ft	2,205	44.10	32.70	111
200 ft	4,410	88.20	65.30	221

Sand for 100 ft of 2 ft barrier by weight of a bag

The bag count does not change with the fill weight; the sand does. 5% extra bags.
Sand per bag	Bags	Sand (tons)	Sand (cu yd)
30 lb	2,205	33.10	24.50
35 lb	2,205	38.60	28.60
40 lb	2,205	44.10	32.70

Corps guidance for sandbag walls (not calculated)

Typical figures from the sources listed below, shown as guidance. They are not results of this calculator, and your emergency management office comes first.
Item	Typical guidance
Height	3 ft is the preferred limit; 5 ft is the practical limit. Taller needs an engineer
Freeboard	Build at least 1 ft above the expected water level
Bag fill	Half to two-thirds full, folded or untied, about 30 to 40 lb
Bag size	About 14 to 18 in wide and 30 to 36 in long when empty, 14 × 24 in in the Corps pamphlet
Pyramid	Base three times the height; stagger the joints and tamp each bag
Seal	Plastic sheeting over the flood side, held with a bag or two at the toe

Methodology & assumptions

Bags come from the US Army Corps of Engineers table for a sandbag levee built as a pyramid, whose base is three times its height: bags per 100 linear ft are 600 at 1 ft, 2,100 at 2 ft, 4,500 at 3 ft and 7,800 at 4 ft (the calculator stops at 4 ft and asks for an engineer above 3 ft). Other Corps districts print a different 1 ft row (800 bags) and shorter 2 and 3 ft rows, so the count is an estimate; a district's own table for your area wins. Heights between the rows are interpolated in a straight line, which is an estimate, and below 1 ft the line runs back to zero. The single-row wall uses the Corps' one figure for it, 300 bags per 100 ft for a wall 1 ft high, so 3 bags per foot of length per foot of height, and the calculator offers it only up to 1 ft. The extra for split or lost bags (5% by default) is a planning allowance, not a Corps figure. Sand weight is the bag count × the weight you pick (30, 35 or 40 lb: a bag filled half to two-thirds full holds about this much damp sand) ÷ 2,000 for short tons; volume divides that by 1.35 tons per cubic yard, the sand density the sand calculator on this site uses (damp sand ranges from about 100 to 130 lb per cu ft, so ask your supplier). The labor figure divides the bag count by 20 bags per person-hour to fill, a planning rule from a municipal sandbag guide; other guides quote 40 to 60 bags per person-hour including stacking, so treat it as a rough guide. It does not include the plastic sheeting, hauling, or placing. The pyramid base width is 3 × the height; some Corps pamphlets give 2.5 ft of width for each foot of height from the bag sizes, so leave some room. The metric toggle shows the length and height in m and the sand in tonnes and m³.

How to estimate the sandbags and sand for a flood barrier

Check with your emergency management office. Ask what height you need, whether bags and sand are supplied, and where to build. Build at least 1 ft above the water level they expect.
Measure the barrier. Enter the length along the line you will protect and the height (the preferred range is 1 to 3 ft). Above 3 ft, ask an engineer.
Pick the wall type and the sand per bag. Use the pyramid unless the wall is 1 ft or lower and short, where the single row is allowed. Pick the sand per bag (a bag half to two-thirds full holds 30 to 40 lb).
Read the bags, sand and labor. The calculator gives the bags, the sand in tons and cubic yards, the base width and the person-hours to fill them.
Fill and stack. Fill the bags half to two-thirds full, lay them in staggered courses with the folded ends under, tamp each one, and build the pyramid with the base three times the height. Cover the flood side with plastic.

Worked examples

Project	Result
100 ft barrier, 2 ft high pyramid, 5% extra, 40 lb bags	2,205 bags, 44.10 tons of sand, 32.70 cu yd, 111 person-hours to fill
50 ft barrier, 3 ft high pyramid, 5% extra	2,363 bags, 47.30 tons of sand, 35 cu yd, 119 person-hours
100 ft barrier, 1 ft high pyramid, no extra	600 bags, 12 tons of sand, 8.90 cu yd
100 ft barrier, 1 ft high single row, no extra	300 bags, 6 tons of sand, against 600 bags for the 1 ft pyramid
100 ft barrier, 2 ft pyramid with 30 lb bags	2,205 bags, 33.10 tons of sand, 24.50 cu yd
10 ft doorway barrier, 1.5 ft high pyramid (an interpolated height)	142 bags, 2.84 tons of sand, 8 person-hours

Frequently asked questions

How many sandbags do I need for a flood barrier?: The Army Corps of Engineers pyramid table gives bags per 100 ft of barrier: 600 at 1 ft high, 2,100 at 2 ft, 4,500 at 3 ft and 7,800 at 4 ft. A 100 ft barrier 2 ft high is 2,100 bags, 2,205 with 5% extra for split bags. Taller walls need many more bags for each foot because the base grows with the height. These are the Portland District's rows; other Corps districts print slightly different ones (800 bags at 1 ft, 2,000 at 2 ft), so the count is an estimate.
How much sand do I need for sandbags?: Bags × the sand in each. A bag filled half to two-thirds full holds about 30 to 40 lb of damp sand. 2,205 bags of 40 lb is 44.10 tons, 32.70 cu yd at 1.35 tons per cu yd; at 30 lb a bag the same wall is 33.10 tons. NDSU Extension puts a cubic yard of sand at roughly 75 bags of 40 lb or 100 bags of 30 lb, using a denser 110 lb per cu ft, so its volumes come out a little lower than this calculator’s. Weights are for damp sand; dry sand is lighter, wet sand heavier.
Why is the base three times the height?: The Corps builds a sandbag levee as a pyramid with a base about three times as wide as it is tall, so the bags lean on each other and the wall does not roll or slide. A 2 ft wall is 6 ft wide at the base and a 3 ft wall 9 ft. That width is why a tall wall uses so many bags. Some Corps pamphlets size the width from the bags themselves (3 bags wide is about 2.5 ft), so leave some extra room.
How high can a sandbag wall be?: Three feet is the preferred limit and 5 ft the practical limit in the Corps’ St. Paul District guidance; above that, use other means or an engineer. This calculator counts bags up to 4 ft (the Corps table stops there), shows a note above 3 ft, and counts none above 4 ft. Build the wall at least 1 ft higher than the water you expect. A 3 ft barrier 50 ft long needs 2,363 bags and 47.30 tons of sand.
When is a single row of sandbags enough?: The Corps gives one single-row figure: 300 bags per 100 ft for a wall 1 ft high, one bag wide with the bags lying lengthwise. That is 300 bags for 100 ft, against 600 for a 1 ft pyramid. A single row is narrow and easily pushed over, so use it for short, low diversions where the water is shallow and slow; the calculator allows it only up to 1 ft.
How long does it take to fill sandbags?: A municipal planning rule is 20 bags per person-hour to fill them, which puts 2,205 bags at about 111 person-hours; other guides quote 40 to 60 bags per person-hour with a good crew, a funnel and a stacker. This is a rule of thumb and not a Corps figure; hauling and placing take extra time, and heavy bags slow people down. Two people filling and a third tying or stacking is a common team.
How full should I fill a sandbag?: About half to two-thirds full, so the bag can be laid flat and the top folded under, which makes it lie tight against its neighbours. A bag filled to the top is round and does not stack. Untied bags are the Corps’ usual choice for a wall; bags that will be moved or thrown are tied. Filled to this level a bag weighs about 30 to 40 lb: a weight one person can lift with good form, not more.
How many sandbags do I need for a doorway?: A 3 ft wide door 1 to 1.5 ft high is a short run: 10 ft of 1.5 ft barrier, a little more than the door width on each side, is 142 bags with 5% extra. Short, low barriers like this slow shallow water but do not stop it, and they should be sealed with plastic.
Do sandbags stop a flood?: They slow and divert shallow water for a while; they do not make a watertight seal, and they are not an engineered flood wall. Laying heavy plastic sheeting over the flood side of the wall and weighting its toe cuts seepage a lot. Water will still come through and under, so plan a sump pump, and move valuables and anything electrical up and out. Follow your local emergency management office, which may supply bags and sand.

Handy tools

Cubic Yards to Tons: Convert the sand to cubic yards or tons for the yard’s ticket, at your own sand weight.