How Much Silage Do You Need for Winter 2026?
Running out of silage mid-winter is every farmer's nightmare — but over-ordering ties up capital and clamp space. This calculator gives you a precise tonnes figure based on herd size, liveweight, DM intake percentage, silage dry matter content and housing duration.
The Formula
(Live weight × DM % × head × days) ÷ silage DM % ÷ 1000 = tonnes fresh weight
Typical DM Intake Rates
Beef cattle
2.0–3.0%
Dairy (dry)
2.5–3.0%
Dairy (milking)
3.0–4.0%
Sheep
2.0–3.0%
Silage DM Reference Values
Pit silage (1st cut)
25–35%
Pit silage (2nd cut)
20–28%
Big bale silage
40–50%
Dry hay
83–87%
Example Calculation
- 100 beef cattle × 550 kg × 2.5% DM for 180 days at 30% silage DM → 825 tonnes fresh weight
- 50 dairy cows × 650 kg × 3.5% DM for 160 days at 28% silage DM → 650 tonnes fresh weight
- Adding a 12% safety margin to the first example → 924 tonnes to order
Frequently Asked Questions
- How accurate are these calculations?
- Based on AHDB guidelines. Accuracy depends on knowing your actual silage DM % — lab analysis is worthwhile for large herds.
- What if my silage DM varies between clamps?
- Run the calculator separately for each clamp and add the totals together. Wet early-cut (20–25% DM) needs 20–30% more volume than dry late-cut.
- Do supplements reduce silage needs?
- Yes — every 1 kg of concentrate reduces forage DM requirement by roughly 0.6 kg. Reduce your DM intake % accordingly.
- Is this calculator for beef or dairy?
- Both. Use 2–3% DM intake for beef and 3–4% for dairy. The calculator works for any liveweight.