Hay & Silage Storage Calculator & Bales Needed & Days It Lasts
Plans fodder for cattle
Plan your fodder both ways — how much hay or silage (and how many bales) a herd needs for a period, or how long the bales you've stored will last.
Feeding 20 animals about 12 kg each for 120 days takes roughly 29 tonnes of fodder — about 144 bales at 200 kg each. The herd eats 240 kg a day.
Next: add 10–15% for wastage and refusal, and a buffer for a long dry spell. Store bales dry and off the ground, and feed in racks to cut losses. Pair with the Livestock Feed Calculator for the full ration.
Bale weights are nominal and vary with crop, moisture and packing. Weigh a few of your own bales for accuracy.
Hay & silage — key facts
- Daily intake
- ≈ 2–2.5% of body weight
- Cow hay/day
- ≈ 10–12 kg
- Need
- animals × kg/day × days
- Days lasts
- stock ÷ herd daily use
- Small square bale
- ≈ 20 kg
- Round bale
- 200–450 kg
- Add buffer
- 10–15% for wastage
- Privacy
- Runs in your browser; nothing uploaded
Never run short of fodder
Running out of stored fodder mid-season means buying in at peak prices or thin, hungry stock — both costly. This tool sizes the problem in two directions. In need mode it multiplies your herd size by the daily fodder per animal and the number of days to cover, giving the total tonnage and the number of bales to put away. In have mode it takes the bales or weight already in store and divides by the herd's daily use to tell you how many days it will last.
Because bale weights differ so much — a 20 kg square bale versus a 600 kg wrapped silage bale — the tool lets you pick the bale type or enter the real weight, so the count is realistic. Add 10–15% for feeding wastage and spoilage and a margin for a long dry spell, store bales dry and off the ground, and pair this with the Livestock Feed Calculator to set the daily ration in the first place.
Size the winter store
Get the tonnes and bales to put away to feed the herd through a dry season.
Check what you have
See how many days your current bales will last so you can act before you run short.
Any bale type
Switch between square, round and wrapped silage bales, or enter your own bale weight.
Plan the buy-in
Spot a shortfall early and budget to buy fodder before prices climb.
Frequently Asked Questions
How much hay does a cow need per day?+
A rough guide is about 2–2.5% of body weight in dry fodder per day, so a 400–500 kg cow eats roughly 10–12 kg of hay daily. Enter your own per-animal figure and the tool scales it to the herd and the period to give the total fodder and bales needed.
How many bales do I need for the winter?+
Multiply animals × daily fodder per animal × the number of days, then divide by the bale weight. For 20 animals at 12 kg/day over 120 days that's 28,800 kg — about 96 round bales at 300 kg each. The tool calculates it and rounds bales up.
How long will my stored bales last?+
Switch to 'how long will it last' mode and enter your bale count (or total weight) and the herd's daily use. The tool divides the stock by the daily requirement — for example 30 tonnes feeding a herd eating 240 kg/day lasts about 125 days.
How much does a bale of hay weigh?+
It varies by type: small square bales are around 20 kg, large square bales ~350 kg, round bales 200–450 kg, and wrapped silage bales ~600 kg (heavier because of moisture). Pick the bale type in the tool, or weigh a few of your own for accuracy.
Should I add a buffer to the calculation?+
Yes — add about 10–15% for feeding wastage, refusal and spoilage, plus an extra margin for a longer-than-expected dry spell or winter. It's far better to have surplus fodder than to run short mid-season.
What's the difference between hay and silage?+
Hay is dried fodder (low moisture, stored loose or baled), while silage is fermented under exclusion of air at higher moisture, usually wrapped or in a pit. Silage bales are much heavier per bale; account for that by choosing the wrapped-bale type or entering the actual weight.
How should I store bales to reduce losses?+
Keep them dry and off bare ground — on pallets, gravel or under cover — to prevent moisture wicking and rot. Stack to shed rain, and use older bales first. Poor storage can waste a large share of round bales left out in the open.
Does this work for goats and sheep too?+
Yes — it works for any ruminant. Just enter the appropriate per-animal daily fodder (much less for a goat or sheep than a cow) and the tool scales the totals and bale count accordingly.
Can I plan a mix of stored and grazed feed?+
Use the daily per-animal figure for just the stored-fodder portion (the part not met by grazing or green fodder). The tool then sizes the hay/silage you need to fill the gap over the period.
How accurate is the bale count?+
It's exact for the weights you enter, but bale weights vary with crop, moisture and packing, so treat the count as a close estimate. Weighing a sample of your own bales gives the most reliable result, and the buffer covers the rest.