How Many Ratchet Straps Do I Need?

How Many Ratchet Straps Do I Need?

Using too few ratchet straps is one of the most common load securing failures found at DVSA roadside inspections. It is also one of the most avoidable. The calculation for how many straps you need is straightforward once you understand the underlying principle — and getting it right is the difference between a compliant load and a prohibition notice.

The Short Answer

The number of ratchet straps you need depends on three things: the weight of your load, the lashing capacity (LC) of your straps, and the method you are using to secure the load. There is no single universal answer — a 1,000 kg pallet secured with over-the-top lashing needs a different number of straps to a 10,000 kg steel coil secured with direct lashing — but the calculation is always the same.

Understanding Lashing Capacity (LC)

Every ratchet strap has a lashing capacity rating printed on its label, expressed in kilograms or decanewtons (daN). The LC is the maximum tension force the strap can apply in normal use — it is not the breaking force. Common LC ratings you will see on LOADICO straps include:

  • LC 500 kg (5 kN) — light securing, smaller loads
  • LC 1,000 kg (10 kN) — standard HGV lashing
  • LC 2,000 kg (20 kN) — heavy duty applications
  • LC 5,000 kg (50 kN) — heavy loads, machinery
  • LC 10,000 kg (100 kN) — very heavy industrial loads

Always work from the LC rating when calculating how many straps you need. Never use the minimum breaking force (MBF) figure — see our guide on understanding MBF vs LC for the full explanation.

Over-the-Top Lashing: The Simplest Calculation

Over-the-top lashing is the most common method for flatbed HGV loads — straps run over the top of the load and hook to anchor points on both sides of the trailer. For this method, EN 12195-1 gives a straightforward rule of thumb:

Total LC of all straps combined ≥ weight of the load.

So for a 4,000 kg load:

  • Four straps at LC 1,000 kg each = 4,000 kg total ✔
  • Two straps at LC 2,000 kg each = 4,000 kg total ✔
  • Three straps at LC 1,000 kg each = 3,000 kg total ✘ (not enough)

This is the minimum. In practice, it is good practice to add one additional strap as a margin, particularly for loads that may shift or where the strap angle is not ideal.

Direct Lashing: A More Complex Calculation

Direct lashing attaches straps directly from the load to trailer anchor points rather than running over the top. It is more efficient per strap — each strap can restrain more load — but the calculation takes into account the angle of the strap and the friction between the load and the trailer bed.

For direct lashing, the EN 12195-1 calculation involves:

  • The angle of each strap relative to the horizontal (steeper angles = more effective)
  • The friction coefficient of the load surface and trailer bed
  • The forces acting on the load in forward, rearward, and lateral directions

For most practical purposes, a transport engineer or experienced load planner should confirm direct lashing calculations for heavy or irregular loads. For standard palletised freight on flatbed trailers, over-the-top lashing with the combined LC rule is the most commonly applied method.

Minimum Numbers by Load Weight: A Practical Reference

Using LC 1,000 kg straps with over-the-top lashing as a baseline:

  • Up to 1,000 kg: minimum 1 strap (2 recommended for stability)
  • 1,001–2,000 kg: minimum 2 straps
  • 2,001–3,000 kg: minimum 3 straps
  • 3,001–4,000 kg: minimum 4 straps
  • 4,001–5,000 kg: minimum 5 straps (or 1 x LC 5,000 kg strap, though multiple straps provide better stability)
  • Up to 10,000 kg: minimum 2 x LC 5,000 kg straps, or 10 x LC 1,000 kg straps

For loads above 10,000 kg or irregular shapes such as machinery, pipes, or steel coils, a combination of chain lashing and webbing straps is typically used. See LOADICO's lashing chain range for high-capacity options.

Load Shape and Stability: Why Numbers Alone Are Not Enough

The number of straps is only part of the picture. Strap placement matters too. Straps should be positioned:

  • As close to the ends of the load as practical, to prevent tipping
  • Evenly spaced along the length of the load
  • At angles as close to perpendicular to the trailer bed as possible for over-the-top lashing
  • Away from sharp edges that could cut the webbing (use edge protectors where needed)

A load secured with six straps clustered in the middle is less stable than one secured with four straps correctly distributed. Number and placement work together.

After the First 25 Miles: Re-Tension Your Straps

Even with the correct number of straps, webbing can bed in and lose tension over the first section of a journey. The DfT Load Securing Guide recommends stopping after approximately 25 miles to check and re-tension all straps. A strap that was correctly tensioned at the depot may have lost significant tension by the time you reach the first motorway.

Choosing the Right Straps

If you are unsure which straps to buy for your typical loads, LOADICO's ratchet strap range covers LC ratings from 500 kg to 10,000 kg. See our guide on how to choose the right ratchet strap for guidance on matching strap specification to your loads, or browse by LC rating to find the right option for your fleet.

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