Ratchet Strap Calculator
How many straps do I need? · EN 12195 method · Strap angle correction · UK farm & trailer transport
5T Ratchet Straps (LC 2500 daN)
The standard size for most farm trailer and machinery transport
10T Ratchet Straps (LC 5000 daN)
For large tractors, combines, and heavy plant — 75mm or 100mm webbing
Lashing Chains & Shackles
Grade 80 chain with shorteners for tying down heavy machines
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Calculate straps needed
Total mass of the load being secured
LC (Lashing Capacity) — shown on the blue label, in daN (1 daN ≈ 1 kg)
Shallower angles reduce effective strap capacity significantly
This calculator uses the EN 12195-1 simplified method for top-over lashing. For loads over 5,000 kg or specialist transport, consult a qualified load securing assessor.
Enter load weight
Results appear here instantly
Ratchet Strap Edge Protectors
Protect webbing from sharp edges on machinery — and protect paintwork from strap abrasion
Bow Shackles (Rated)
Galvanised rated bow shackles for attaching chains and straps to lashing rings
Trailer Lashing Rings (D-Rings)
Weld-on or bolt-on D-rings to add proper lashing points to a trailer or flatbed
Wheel Chocks (Pair)
Rubber wheel chocks for securing wheeled machinery before strapping — chocking is not optional for vehicles
Cargo Nets — Trailer Size
Heavy elastic or knotted net for loose loads on trailers — bale fragments, top soil, grain spillage
Ratchet Strap Storage Bag
Keeps straps untangled and dry — makes finding the right strap fast when you're in a hurry
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Why strap angle matters — and why most farmers get this wrong
A ratchet strap only develops its full rated LC when it runs at 90° to the trailer bed — perfectly vertical. In practice, straps on a flat trailer typically run at a much shallower angle because the lashing points are at the same height as the trailer floor. At 45° (the typical angle on most flat trailers), the strap only delivers 71% of its rated LC as useful vertical and forward restraint.
90°
100%
Full rated LC
45°
71%
of rated LC
30°
50%
of rated LC
The calculator accounts for this: select your actual strap angle and it adjusts the effective per-strap contribution automatically. On a typical flat trailer at 45°, you will often need more straps than you might expect based on the rated LC alone.
Never strap at less than 30° to the horizontal. Below this angle the strap contributes almost nothing to keeping the load on the trailer and is more likely to chafe on edges. Raise lashing points using stanchions, trailer headboards, or purpose-built strap anchor points to steepen the angle.
UK law on load securing — what DVSA looks for
Under the Road Vehicles (Construction and Use) Regulations 1986 and Highway Code Rule 98, all loads on UK public roads must be properly secured. DVSA officers can stop and inspect any vehicle at any time — and can prohibit it from moving if the load securing is inadequate.
All straps must carry a legible EN 12195-2 blue label
A strap with a faded or missing label has no legally recognised LC figure. Replace it.
Lashing points must be structural
Body panels, fuel tanks, and non-rated hooks are not legal lashing points. Use purpose-built D-rings or manufacturer-designated chassis points.
This applies to all road movements — even short ones
Moving a tractor half a mile between fields on a public road requires compliant load securing. Distance does not reduce the legal obligation.
A load that falls from a vehicle is a criminal matter
Prosecution under the Road Traffic Act is possible. The driver, operator, and vehicle owner can all be liable.