Tie-down requirement
The tie-down requirement calculator compares two separate arithmetic tests: minimum count by cargo length and weight, and aggregate working load limit. It uses the federal general-cargo rules for an article not blocked against forward movement. Enter the strap’s marked WLL and attachment method; the result does not certify every aspect of securement.
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Two straps can satisfy different tests at once
For a hypothetical 700 lb ATV measuring 7 ft, the general length rule requires two tie-downs. With 1,100 lb WLL straps attached at one end to an anchor and at the other to the machine, each contributes 550 lb. Two contribute 1,100 lb against the required 350 lb aggregate WLL.
Using a stronger single strap would not satisfy the separate two-strap count in that example. Breaking strength is a different figure: use the manufacturer’s marked WLL rather than an assumed multiplier.
Check routing, anchors and movement
An eligible strap running between anchors on both sides over or through the load contributes its full WLL. The independent minimum count still applies. Anchor capacity, attachment points, strap condition, blocking and restraint in every direction remain separate checks; follow the machine and trailer instructions.
The relevant provisions are 49 CFR 393.110, count and 393.106(d), aggregate WLL. Their commercial-vehicle scope does not establish the private-hauling rules for every state. The securement guide covers those distinctions.
- Transport
- Tie-down requirement; The tie-down requirement has two federal tests that apply at once, and either can be the binding one.
Transport
Enter the machine's weight and length, the working load limit on one strap and how many straps you plan to use. The calculator returns the minimum number of tie-downs, whether your straps' combined rating is enough, and which of the two tests sets the answer. The tie-down rules guide explains the rule behind each number; What each of the five inputs asks for.
- Weight of the machine
- Sets the aggregate rating requirement: half this figure; Entering a combined weight for two machines; each is secured separately.
- Length on the deck
- Sets the minimum tie-down count, independently of weight; Guessing. Most machines land in the 5–10 ft band, where the minimum is two.
- Working load limit per strap
- The only strength figure the rule counts; Using breaking strength, which is roughly three times higher.
- Number of straps
- Checked against both the count rule and the rating rule; Assuming more rating substitutes for more straps: it does not.
- Attachment method
- Decides whether each strap contributes half its rating or all of it; Not knowing this is a choice; rerouting is cheaper than buying straps.
For why the count rule usually governs on powersports machines, why the working load limit and not the breaking strength is what counts, and how routing a strap changes its contribution, read the tie-down rules guide.
Working load limit marked on one strap (lb)
Use the WLL on the strap’s own tag. Breaking strength is a different rating; an assumed three-to-one conversion does not establish the WLL for the particular tiedown or its installed arrangement.
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How the tie-down count is calculated
The two formulas
Count test: the minimum number of tie-downs comes from the length of the cargo (49 CFR 393.110). Rating test: the working load limits of all the tie-downs, added together, must be at least half the cargo weight (393.106). A tie-down anchored at one end counts half its marked limit and one anchored at both ends counts all of it (393.108). The answer is whichever test needs more straps.
Assumptions behind the tie-down result
These are the federal general cargo rules, which apply directly to commercial carriers. Most states apply an equivalent standard to private hauling, and enforcement varies; this is the floor, not the ceiling.
Straps are in serviceable condition, correctly rated, and anchored to rated anchor points and not to trailer railings or fenders.
Suspension movement can change tiedown tension over bumps. Follow the machine and tiedown makers’ approved attachment and suspension-loading instructions; wheel restraints and frame attachments do not necessarily use the same procedure.
Each machine is counted separately. Two machines on one trailer are two securement problems, not one.
Worked tie-down examples
Given: A 700 lb utility ATV, 7 ft long, with 1,100 lb WLL ratchet straps anchored at one end.
Work: Length is over 5 ft and up to 10 ft, so the minimum count is 2. Required aggregate WLL = 700 ÷ 2 = 350 lb. Each one-end strap counts 550 lb, so a single strap already clears the rating, but the count rule still says 2.
Result: Two straps. The count, not the rating, is what sets the number here.
Given: A 480 lb dual-sport, 7 ft long, with 400 lb WLL straps anchored at one end; Work: Minimum count 2. Required aggregate = 240 lb. Each strap counts 200 lb, so two straps give 400 lb aggregate; Result: Two straps meet both tests, though four points is what actually stops it moving sideways.
When a tie-down question needs a professional opinion
If a strap is cut, frayed, chemically burned or has a damaged ratchet, it has no rating at all: replace it instead of adding another.
Never hook a strap to a handlebar, a brake line, a plastic fender or a fork tube. Anchor to the frame, the triple clamp with a proper strap, or a rated tie-down point.
If you are hauling commercially, the full text of the rule governs and there are conditions this calculator does not model, including front-end structure and blocking requirements.
Where the tie-down values come from
Protection Against Shifting and Falling Cargo: general securement rules : U.S. Government Publishing Office (eCFR), 49 CFR §§ 393.100–393.114.
What are the general requirements for securing articles of cargo? : U.S. Government Publishing Office (eCFR), 49 CFR § 393.106.
How is the working load limit of a tiedown determined? : U.S. Government Publishing Office (eCFR), 49 CFR § 393.108.
Cargo Securement Rules: driver and carrier guidance : Federal Motor Carrier Safety Administration.
Calculator version 1.0.0. Saved results record this version and your inputs, so a later formula change never rewrites an old result.
Tie-down requirement questions
How do I measure the length of my machine for this?
Along the trailer deck, front tire to rear tire, as it will sit. That is the dimension the count rule uses. Most motorcycles and ATVs come out between six and eight feet, which puts them in the band where the minimum is two tie-downs regardless of weight, which is usually the binding test.
Where is the working load limit on my strap?
On the strap’s own tag, sewn into the webbing, usually stating both the working load limit and sometimes the breaking strength. If the tag is missing or illegible, the strap has no rating you can count toward the aggregate requirement, whatever it is capable of, so replace it, not assuming.
What does anchored at both ends mean exactly?
The tie-down is attached to a rated anchor point at each end and passes over, through or around the cargo in between, not terminating at a hook on the machine. Routed that way it contributes its full working load limit; routed with one end hooked to the machine it contributes half. It is the routing, not the strap, that changes.
Do I run this once for two machines or twice?
Once per machine. Each machine is a separate article of cargo under the rule, with its own minimum count based on its own length and its own aggregate rating requirement based on its own weight. Two machines on one trailer are two securement problems, not one problem with a bigger number.
What if my straps are different ratings?
Run it with the lowest rating in the set, which gives a conservative answer, or work out the aggregate by hand by adding each strap’s contribution according to how it is attached. The calculator assumes a single rating for clarity; the rule itself simply adds the contributions of every tie-down on the article.
Is a damaged strap still worth something?
No. A cut, frayed, chemically burned or heat-damaged strap has no rating, and neither does one with a damaged ratchet. You cannot compensate by adding another, because the rule counts rated capacity and a damaged strap has none to count. Replace it, not supplementing it.
- Tie-down rules: the regulation behind these numbers
- Both tests explained, with the practice the rule does not cover.
Trailer load match: check the weights first; Securement only matters once the load is inside every rating.
Tire size change calculator; A taller tire raises the loaded height you have to strap down.
- Ramp angle, breakover and safe loading
- The practices that prevent the common loading injuries.