Tandem Hole Chart by State 2026: Bridge Formula & ~250 lb/Hole
The chart page drivers search for: typical pounds shifted per tandem pin hole, 4-hole vs 5-hole planning math, federal bridge formula spacing recap, and state exceptions (CA, IL, MI, NY and more). Procedure how-to lives on our sliding tandems guide — this page owns the numbers.
~250 lb
Common Per-Hole Plan
200–500 lb
Typical Real-World Band
Bridge
Spacing Still Matters
Reweigh
Chart ≠ Scale Ticket
Ahmad Qazi
Founder & CEO, O Trucking LLC
Fact-Checked by O Trucking Dispatch Team
5+ years helping carriers plan axle weights, permits, and CAT Scale corrections across 48 states
Written by Ahmad Qazi, founder of O Trucking LLC, drawing on 9+ years dispatching for owner-operators. Learn more about us.
O TruckingTandem Hole Chart by State 2026
Key Takeaways
- This is the CHART page; step-by-step sliding lives on sliding-tandems-weight-distribution.
- Typical per-hole transfer: ~200–500 lb; ~250 lb is a common conservative planning figure.
- 4 holes ≈ 1,000 lb planned; 5 holes ≈ 1,250 lb planned — always verify on a scale.
- Bridge formula and KPRA can fail you even when 12k/34k/34k look fine.
- CA, IL, MI, NY and others deserve extra spacing checks beyond federal Interstate baselines.
- CAT Scale: weigh → calculate holes → slide → reweigh before the coop.
Distinct from the Sliding How-To
Master Per-Hole Planning Chart (2026)
Hole spacing on many van slider rails is roughly 6 inches. Transfer per hole is not a physics constant — dense rear freight shifts differently than a light, high center-of-gravity load. Use the bands below for planning, then trust the scale.
| Holes Moved | @ 200 lb/hole | @ ~250 lb/hole | @ 400 lb/hole | @ 500 lb/hole |
|---|---|---|---|---|
| 1 | 200 | 250 | 400 | 500 |
| 2 | 400 | 500 | 800 | 1,000 |
| 3 | 600 | 750 | 1,200 | 1,500 |
| 4 | 800 | 1,000 | 1,600 | 2,000 |
| 5 | 1,000 | 1,250 | 2,000 | 2,500 |
| 6 | 1,200 | 1,500 | 2,400 | 3,000 |
| 8 | 1,600 | 2,000 | 3,200 | 4,000 |
Related limits: axle weight limits and grossed-out weight limits by state.
4-Hole vs 5-Hole Planning
Drivers often talk in "I slid four" or "I slid five." Using the ~250 lb conservative column:
Four holes
≈ 1,000 lb planned transfer. Common fix when drives show ~800–1,200 over and trailers have room.
Five holes
≈ 1,250 lb planned transfer. Use when you are closer to 1,200–1,500 over and trailer group is light enough.
If the trailer group is already near 34,000 lbs, sliding weight onto it solves drives by creating a trailer overweight. That is when fifth-wheel slides or a reload — not more holes — is the real answer. See the sliding guide for sequence.
Federal Bridge Formula Recap (Why Holes Change Legality)
The Federal Bridge Formula ties allowable weight to how far apart axles are spread and how many axles are in the group. Sliding tandems changes distances — especially kingpin to rear axle (KPRA) on the trailer — so hole counts are also spacing decisions.
Practical takeaway
Do not memorize the full formula at the scale booth. Know that (1) wider spreads often allow more group weight, (2) shoving tandems to extremes can violate KPRA/bridge even when axle pounds look pretty, and (3) FHWA publishes official bridge-formula calculators — use them when a load is within a few hundred pounds of any limit.
Interstate baselines drivers quote constantly — 80,000 GVW, 20,000 single, 34,000 tandem — are not a free pass on every state road or every spacing. Permit loads and non-Interstate routes are their own charts.
State Exceptions Drivers Chart For (Typical)
Exact statutes change. Treat the following as typical 2026 planning flags, then confirm with state DOT / enforcement publications for your trailer type before you depend on a hole count.
| State | What to Watch | Hole-Chart Implication |
|---|---|---|
| California | KPRA limits (often discussed ~40 ft for many setups) + strict CHP scales | Do not slide holes that push KPRA illegal even if axles improve |
| Illinois | Bridge-formula enforcement; busy Interstate scales | Reweigh after slides; spacing citations happen |
| Michigan | Unique axle/bridge culture; seasonal frost/weight issues inland | Do not assume 80k Interstate logic on every MI route |
| New York | Strict weighing culture; bridge/overweight sensitivity | Prefer conservative hole estimates + mandatory reweigh |
| Texas / many Southern | Generally familiar 80k patterns on Interstates; watch non-Interstate & permits | Standard hole chart often works — still reweigh |
| Northern freeze-law states | Seasonal reduced limits on some roads | Hole math cannot invent weight capacity that frost laws removed |
Direction Cheat Sheet (Weight Follows the Slide Logic)
Charts without direction cause expensive backwards slides:
- Drives heavy / trailer light: slide trailer tandems back (toward the rear) to move weight onto trailer axles.
- Trailer heavy / drives light: slide tandems forward to move weight onto drives.
- Steer issues: often a fifth-wheel problem more than a tandem-hole problem.
CAT Scale Workflow With This Chart
- 1
Pull a full CAT Scale ticket (steer / drive / trailer). See how to use a CAT Scale.
- 2
Note pounds over on the heavy group and pounds of room on the light group.
- 3
Divide overweight by your planning factor (start with ~250 if unsure). Round up one hole for safety margin.
- 4
Check KPRA / bridge constraints for the states ahead — especially CA.
- 5
Slide, seat pins, reweigh ($3-class reweigh is cheaper than any overweight ticket).
- 6
Only then approach the coop — illegal skips are covered separately in skip weigh station fines.
Worked Examples
Example A — Drives 1,100 over
Ticket: steer 11,600 · drives 35,100 · trailer 31,800 · gross 78,500.
Drives 1,100 over a 34k tandem cap; trailer has ~2,200 lbs of room. 1,100 ÷ 250 ≈ 4.4 → slide 5 holes back, reweigh. Confirm KPRA still legal for CA if that is tonight's destination.
Example B — Trailer 900 over
Ticket: steer 11,400 · drives 32,500 · trailer 34,900 · gross 78,800.
900 ÷ 250 ≈ 3.6 → slide 4 holes forward, reweigh. If drives were already near 34k, stop and consider fifth-wheel or freight shift instead of dumping overweight onto drives.
Example C — Axles legal, bridge illegal
All groups under common caps but KPRA pushed past California limit after an aggressive rear slide. Fix: slide forward enough to restore legal KPRA even if it reintroduces a smaller axle imbalance you solve with fifth-wheel or a partial reload. Hole charts without spacing checks create this failure mode.
Build Your Own Empirical Chart
Owner-operators who want help pre-screening heavy freight before it becomes a scale problem can use O Trucking dispatch. Drivers comparing seats after too many weight fights can browse careers.
When the Hole Chart Is the Wrong Tool
Tandem holes move weight between drives and trailer groups. They do little for a light steer axle paired with heavy drives if the fifth wheel is too far back. They also cannot fix a true gross overweight — sliding does not delete pounds from the truck. If gross is over 80,000 (or your permit cap), you need a reload, permit, or refusal — not eight more holes.
| Problem on Ticket | First Tool | Hole Chart Role |
|---|---|---|
| Drives heavy, trailer light | Slide tandems back | Primary — use per-hole math |
| Trailer heavy, drives light | Slide tandems forward | Primary — watch KPRA |
| Steer light, drives heavy | Fifth-wheel forward | Secondary after steer fix |
| Gross overweight | Offload / permit / refuse | None — holes do not remove weight |
| Axles OK, KPRA illegal | Restore legal spacing | Constrained — may need freight shift |
Calibrating lb/Hole on Your Trailer
After you have a clean before/after CAT pair for a known hole count, compute your empirical factor: pounds moved on the drive group divided by holes slid. Do this for a nose-heavy dry van load and again for a rear-heavy load if you haul both. Many drivers discover their "250" is really 320 on dense freight and 180 on light, bulky freight. Write both numbers on a cab card. That personal chart beats generic internet tables when you are 40 minutes from a coop.
Spread axles, step decks with permit-locked tandems, and RGN configurations may not offer the same slider freedom as a 53-ft van. If your equipment does not slide, this chart is still useful for understanding why a broker's "just slide it" advice is nonsense — and why you should refuse the load instead.
Dispatch & Shipper Conversations That Prevent Scale Panic
The best hole count is zero because the dock built the load correctly. Before you leave a shipper with a sketchy bill-of-lading weight:
- Ask for pallet counts, piece weights, and whether the nose is intentionally heavy.
- Photograph the load pattern when seals allow visibility or when you load yourself.
- Budget CAT Scale time into HOS before the first open coop on the route.
- Call dispatch early if the first ticket shows a structural problem holes cannot fix.
Tools that help: axle weight calculator and the sliding-tandems how-to for mechanical steps after the chart tells you how far to go.
Frequently Asked Questions
How much weight does one tandem hole move?
On a typical 53-ft dry van slider, drivers often plan on roughly 200–500 lbs of weight transfer per hole between drives and trailer tandems, with many fleets teaching a ~250–450 lb rule of thumb depending on load height and density. Exact shift depends on cargo location, trailer length, fifth-wheel position, and suspension. Always reweigh after sliding — charts are planning tools, not scale tickets.
What is a tandem hole chart used for?
A tandem hole chart helps you estimate how many pin holes to slide to correct an axle overweight before you burn time guessing at the CAT Scale. This page focuses on chart values, bridge-formula spacing, and state quirks. For the step-by-step slide procedure, use our sliding-tandems-weight-distribution guide.
What is the difference between 4-hole and 5-hole tandem settings?
Drivers sometimes describe positions by how many holes they moved from a starting mark, or by rail designs with different usable hole counts. Moving four holes at ~250 lb each is roughly 1,000 lbs of planned transfer; five holes is roughly 1,250 lbs — before real-world variance. Some trailers have more total holes on the rail; what matters is measured spacing and the reweigh.
How does the federal bridge formula affect tandem holes?
The Federal Bridge Formula limits weight based on axle spacing and number of axles. Sliding tandems changes kingpin-to-rear-axle and group spacing, which can make a previously legal set illegal (or vice versa) even if each group is under 12k/34k/34k intuition. California KPRA limits and other state bridge laws add another layer beyond raw federal numbers.
Which states have special tandem or bridge rules drivers must chart for?
California is famous for kingpin-to-rear-axle (KPRA) limits (commonly discussed around 40 feet for many configurations — confirm current CHP/DOT guidance for your trailer). Illinois, Michigan, New York, and others apply bridge-formula enforcement or freeze-law / seasonal twists that change effective limits. Always check the state you will scale in, not only the origin state.
Should I slide tandems before or after the CAT Scale?
Weigh first when possible. Get steer/drive/trailer splits, compute holes needed from this chart, slide, then reweigh. Blind-sliding before any ticket wastes time if the fifth wheel or load placement was the real problem. See cat-scale-how-to-use for ticket workflow.
Can I pass axle limits and still fail bridge formula?
Yes. That is the classic trap: 12,000 / 34,000 / 34,000 looks fine on the ticket, but axle spacing violates bridge formula or a state KPRA rule. Hole charts that ignore spacing create false confidence. Use FHWA bridge formula tools plus state charts when a load is tight.
How do spread axles change the hole chart?
Spread-axle flatbeds (often ~10 ft spreads) are governed differently and frequently do not slide like a van tandem group. They can allow higher group weights under bridge formula in many cases (commonly discussed up to about 40,000 lbs on a qualifying spread — confirm permits and state rules). Do not apply van hole math to a locked spread configuration.
Where can I see legal gross and axle limits by state?
Use our grossed-out-weight-limits-by-state and axle-weight-limits-trucking guides alongside this hole chart. Federal Interstate baselines are typically 80,000 lbs GVW with standard axle caps, but state non-Interstate and permit regimes differ.
Why We Publish Charts Separately from How-Tos
Search intent is chart-first
Drivers Googling tandem hole chart by state want numbers and exceptions — not a 12-step pin tutorial. We keep both pages and cross-link them.
Dispatch screens weight before you leave the shipper
The cheapest hole slide is the one you never need because the load was refused or reworked at the dock. That is part of how we protect carrier CSA scores.
Heavy Freight on Your Own Authority?
O Trucking helps owner-operators pre-screen weights and lanes so the first CAT Scale is a confirmation — not a crisis.