How much does a round silage bale weigh?

A typical round silage bale weighs around 640 kg, but this varies significantly with dry matter percentage, grass species, cutting date and how tightly the baler is set. Wetter grass (lower DM) produces heavier bales with less feed value per kg. A bale at 20% DM may weigh 750 kg while a bale at 35% DM from the same field may weigh 520 kg.

How much does a round hay bale weigh?

A large round hay bale typically weighs 250–350 kg, averaging around 300 kg for ryegrass or meadow hay. Hay is always lighter than silage because it has been dried to 85–90% dry matter. Small square hay bales average 16–25 kg each, making them around 50 bales per tonne.

How much does a straw bale weigh?

Round straw bales typically weigh 150–220 kg, averaging around 180 kg. Straw is lighter than hay because the hollow stems of cereal crops are less dense than grass. Small square straw bales average 14–22 kg. Big square (Hestone-style) straw bales weigh 280–440 kg depending on whether they are 6-string or 8-string.

How many round bales do I get per hectare of silage?

First cut grass silage typically yields 8–13 round bales per hectare (3–5 per acre), assuming 640 kg bales and a typical first-cut yield of 5–8 tonnes dry matter per hectare. Second cut yields 5–8 bales per hectare. Actual bale numbers depend heavily on grass yield, dry matter percentage and baler settings.

How many small square bales to a tonne of hay?

Small square hay bales at an average weight of 20 kg give 50 bales per tonne. At 18 kg they give approximately 56 bales per tonne. At 25 kg they give 40 bales per tonne. Always weigh a representative sample from the field to get an accurate bale count for your specific crop.

How many Hestone 6-string bales to a tonne of straw?

A 6-string Hestone straw bale at an average weight of 350–380 kg gives approximately 2.6–2.9 bales per tonne. An 8-string Hestone bale at 440–480 kg gives approximately 2.1–2.3 bales per tonne. These are approximate figures — weigh a sample bale on a weighbridge or bale weigher for accurate stocking calculations.

Why do silage bale weights vary so much?

Silage bale weight is primarily determined by the dry matter (DM) percentage of the crop at the time of baling. Wetter grass baled at 20% DM produces much heavier bales than drier grass baled at 35% DM — but the heavier bale contains similar amounts of dry matter feed. Baler settings (compression pressure), crop species, growth stage and even bale diameter also affect weight.

What is the cost of big bale silage per tonne in the UK?

Total contractor costs for big bale silage (baling plus wrapping) typically run £12–£21 per bale including materials. Based on a 640 kg bale at 28% DM containing approximately 179 kg of dry matter, this equates to roughly £67–£117 per tonne of dry matter from contractor costs alone, before field costs, fertiliser and establishment are included.

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Reference Guide

Silage, Hay and Straw Bale Weights — UK Reference Guide

Typical weights for every bale type, bales per hectare by crop, Hestone bales per tonne and big bale silage cost — all in one place.

8 min read·Updated May 2026·Forage & Feed

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Bale weights vary more than most people expect. A round silage bale can weigh anything from 520 kg to 800 kg depending on dry matter, grass type and baler settings — and getting the wrong figure in your stocking calculations can leave you short of winter feed by February.

This reference guide covers typical weights for every bale type commonly used on UK farms, bales per hectare and per acre by crop, Hestone big square bale weights per tonne, and a breakdown of big bale silage costs. Use the AgriOps Bale Calculator to run your own numbers once you have your bale weights.

Why Bale Weights Vary So Much

💧

Dry matter %

The biggest variable for silage. Wetter grass at 20% DM produces heavier bales than 35% DM grass — but the heavier bale may contain the same feed value.

⚙️

Baler settings

Contractors often set balers looser for speed. Owner-operators tend to set tighter. The same field can produce bales 15–20% heavier with different baler settings.

🌿

Crop species

Perennial ryegrass is denser than mixed swards. Maize is denser than grass. Wheat straw bales lighter than hay from the same-sized bale.

📅

Cutting date

Earlier cutting = leafier, denser material. Later cutting = more stem, less dense. First-cut silage bales are typically heavier than second-cut.

🌧️

Weather (hay)

Rain during haymaking adds moisture and reduces density. Bales made in ideal conditions can be significantly lighter and drier than rain-affected bales.

📏

Bale diameter

Most round balers produce 1.2m or 1.5m diameter bales. A 1.5m bale contains roughly 56% more material by volume than a 1.2m bale.

UK Bale Weights by Type

Typical weights for UK farm conditions. Always weigh a sample from your own field for accurate stocking calculations.

Silage Bales

Bale Type	Typical Weight	Range	Notes
Round silage bale	640 kg	550–750 kg	Varies with DM%, grass type and wrapping
Big square silage bale	500 kg	450–600 kg	3×3 or 4×4 format
Maize silage round bale	700 kg	650–800 kg	Heavier — maize is denser than grass
Wholecrop silage bale	580 kg	520–680 kg	Cereal wholecrop — similar to grass silage
Haylage round bale	450 kg	380–520 kg	Higher DM than silage — lighter per bale

Hay Bales

Bale Type	Typical Weight	Range	Notes
Round hay bale (large)	300 kg	250–380 kg	Meadow hay or ryegrass — density varies by baler
Small square hay bale	20 kg	16–25 kg	Classic two-string — 50 bales per tonne
Hestone big square (6-string)	380 kg	340–420 kg	~2.7 bales per tonne
Hestone big square (8-string)	470 kg	430–520 kg	~2.1 bales per tonne
American (Hesston) square	500 kg	450–560 kg	Less common in UK — similar to big square silage

Straw Bales

Bale Type	Typical Weight	Range	Notes
Round straw bale	180 kg	150–220 kg	Lighter than hay — hollow stems, less dense
Small square straw bale	18 kg	14–22 kg	55–70 bales per tonne
Big square straw bale	280 kg	240–340 kg	Wheat or barley straw — varies by crop
Hestone straw (6-string)	350 kg	310–400 kg	~2.8 bales per tonne
Hestone straw (8-string)	440 kg	400–490 kg	~2.3 bales per tonne

Get accurate bale weights with a hydraulic bale weigher

Mounts on loader arms — weighs bales as you pick them up. The only reliable way to know your actual bale weight. View on Amazon →

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Bales Per Hectare and Per Acre by Crop

Based on typical UK farm yields and standard round bale weights. Actual figures depend heavily on soil type, fertiliser inputs, cutting management and weather.

Crop	Typical Yield	Bales/ha	Bales/acre	Based on
Grass silage — 1st cut	5–8 t/ha DM	8–13	3–5	640 kg round
Grass silage — 2nd cut	3–5 t/ha DM	5–8	2–3	640 kg round
Grass silage — 3rd cut	2–3 t/ha DM	3–5	1–2	640 kg round
Haylage	3–6 t/ha DM	7–13	3–5	450 kg round
Hay (meadow / ryegrass)	3–5 t/ha	10–17	4–7	300 kg round
Barley straw	3–5 t/ha	17–28	7–11	180 kg round
Wheat straw	4–6 t/ha	22–33	9–14	180 kg round
Oat straw	3–4.5 t/ha	17–25	7–10	180 kg round
Maize silage	12–18 t/ha FM	17–26	7–10	700 kg round

All figures are indicative only. DM = dry matter. FM = fresh matter. Silage yields expressed as tonnes dry matter per hectare. Straw and hay yields as fresh weight tonnes per hectare. Bale counts assume standard UK round bale dimensions.

Free Tool

Bale Calculator

Enter your bale weight, field size and yield to calculate how many bales you'll get and how much feed you have. Works for silage, hay, straw and haylage.

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Hestone Big Square Bales — Weights Per Tonne

Hestone-style big square bales (also made by Hesston, Krone, Claas and New Holland) come in 6-string and 8-string variants. The number of strings affects compression and therefore weight — 8-string bales are significantly heavier and denser than 6-string. The question "how many Hestone bales to a tonne" depends entirely on which configuration and crop you're dealing with.

6-String Hestone

🌾 Hay

2.6–3.1 bales/tonne (340–390 kg avg)

🌿 Straw

2.7–3.2 bales/tonne (310–370 kg avg)

⚫ Silage

1.9–2.4 bales/tonne (420–520 kg avg)

8-String Hestone

🌾 Hay

2.0–2.4 bales/tonne (415–500 kg avg)

🌿 Straw

2.1–2.6 bales/tonne (385–470 kg avg)

⚫ Silage

1.5–1.9 bales/tonne (540–660 kg avg)

Always weigh a sample bale. These are indicative figures only. Big square baler settings, operator preferences and crop conditions create significant variation — the only reliable figure is one from your own bales on a weighbridge or bale weigher.

Big Bale Silage Cost Per Tonne — UK 2026

Big bale silage is more expensive per tonne of dry matter than clamp silage for large herds, but offers flexibility for smaller producers and fields that can't justify a clamp. The total cost depends heavily on whether you use a contractor or own equipment.

Cost Item	Low	High	Per	Notes
Contractor baling charge	£8	£14	per bale	Varies by region and contractor
Wrapping charge (6 wraps)	£4	£7	per bale	6 wraps minimum — 8 recommended for storage
Netwrap (big bale)	£1.20	£2.00	per bale	Bought in rolls — own-wrapped cost
Silage wrap film	£2.50	£4.50	per bale	500mm stretch film — own-wrapped cost
Inoculant (applied)	£0.80	£2.50	per bale	Varies by product and rate
Total contractor cost	£12	£21	per bale	Baling + wrapping combined
Total own-wrapped cost	£3.70	£7.00	per bale (materials)	Excludes tractor and labour time
Cost per tonne DM (contractor)	£19	£34	per tonne DM	Based on 640 kg bale at 28% DM

Contractor costs are UK market rates for 2026 and vary by region. DM cost based on 640 kg round bale at 28% dry matter = 179 kg DM per bale. Field costs, fertiliser, cultivation and reseeding not included.

Baling & silage equipment

Bale Weigher / Indicator

Hydraulic bale weigher for loader arms — weigh bales as you pick them up.

Silage Inoculant

Bacterial inoculant applied at baling — improves fermentation and DM recovery.

Silage Stretch Wrap Film

500mm black silage stretch wrap film — 6–8 wraps recommended per bale.

Netwrap for Round Balers

Round baler netwrap — check your baler specification before ordering.

Silage Additive Applicator

Mounted inoculant applicator for round balers — even coverage across the bale.

Bale Spike / Grab

Heavy duty bale spike for moving round bales with telehandler or loader.

Affiliate disclosure: AgriOps participates in the Amazon EU Associates Programme. Links are affiliate links — we may earn a small commission at no extra cost to you.

Frequently Asked Questions

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Hay vs Straw vs Silage Explained

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All bale weights and yield figures are typical ranges for UK farm conditions and should be used as planning guides only. Actual weights vary significantly with crop, conditions and equipment. Always weigh a sample from your own bales for accurate stocking and feed budgeting calculations. Cost figures are indicative UK market rates for 2026 and will vary by region and supplier.