Agrimetra

Hay bale weight calculator

A 5 × 5 ft round bale packed at 11 lb/ft³ weighs about 1,080 lb, or 490 kg; at 14 % moisture, 929 lb of it is feed. That is 1.85 bales to the US ton, and 40 cows eating 30 lb of dry matter a head a day go through 156 bales over a 120-day winter.

The answer updates as you type — there is no button to press.

e.g. 5 ft.

e.g. 6 ft — on a round bale, the chamber width.

e.g. 10 lb/ft³ for a well-made dry round bale.

%

Dry hay is around 12 % — this is what turns weight into feed.

For the bales-needed line.

e.g. 120 days of winter.

Dry matter, not hay as fed — about 2 % of body weight: 30 lb (13.6 kg) for a 1,500 lb beef cow.

Your answer

One bale weighs1,178 lb

In kilograms
534 kg
Actual feed in the bale (dry matter)
1,037 lb
Bales per US ton
1.7
Bales per tonne
1.87

Field job sheet

Add head to feed, days and daily intake below to see how many bales the herd eats over the period.

How the answer is worked out

A bale’s weight is its volume times how tightly it was packed:

round bale: π × (diameter ÷ 2)² × width × density square bale: width × height × length × density

Two more steps turn weight into feed:

Why the size is not the answer

Two bales of identical size off different balers can differ by a third in weight. Density is where that difference lives, which is why the calculator asks for it rather than printing a “typical” weight. The first bale you weigh is worth more than any table: it gives you the density for the rest of the crop.

Buying and selling by the ton

A price per bale only means something once you know the bale weight. With the bales-per-ton line you can turn a per-bale offer into a per-ton price and compare it with hay priced the other way — and compare two sellers whose bales look the same in the yard.

Planning the winter

  1. Count from your own herd. Heavier cows, cows nursing calves and cold snaps all raise intake above the dry-cow figure.
  2. Plan with a margin. Waste in storage and at the feeder comes on top of what the page counts.
  3. Check early. Running the numbers in the fall, against the bales in the yard, leaves time to buy before hay gets expensive.

A worked example

Every figure below is computed by the calculator above from this case — nothing here is typed in by hand:

Bale shape
Round bale
Bale measured in
ft
Bale diameter
5
Bale length
5
Bale density
11
Density unit
lb/ft³
Moisture
14
Head to feed
40
For how many days
120
Daily feed weighed in
lb
Dry matter per head per day
30

One bale weighs:1,080 lb

In kilograms
490 kg
Actual feed in the bale (dry matter)
929 lb
Bales per US ton
1.85
Bales per tonne
2.04
Total for the whole field
156

Worked by Agrimetra with the same engine the calculator above runs.

What this means in the United States

A round bale has no standard weight: size, density and moisture move it by hundreds of pounds, and hay is bought by the ton and fed by the bale. Feeding out to a known herd for a known number of days is what converts one into the other.

Questions growers actually ask

How much does a round bale of hay weigh?
There is no standard weight. A 5 × 5 round bale can weigh from well under 800 lb to well over 1,200 lb depending on the baler, the crop and the moisture — which is why hay should be bought by the ton, and why this page asks for density instead of assuming one.
How do I find the density of my bales?
Weigh one bale — on a scale, a loader with a load cell, or a truck across the elevator scale divided by the bales on it — and divide by the bale volume the calculator shows. After that, the density carries over to every bale off the same baler and crop.
Why does the calculator want dry matter per head?
Because the moisture in the bale is not feed. A cow's appetite is set in dry matter — about 2 % of body weight for a dry beef cow — and the page divides the herd's dry matter by the dry matter in one bale. Enter the daily figure in pounds or kilograms; switching the unit converts the number you typed.
Does the count include waste?
No. It is what the cattle eat. Bales stored outside and fed without a ring lose a real share to weather and trampling; add that allowance to the bale count yourself, based on how you store and feed.

Last updated:

Sources

Calculators that use the same field