Cab to axle range	Common bed length	Typical use
40 to 42 in	8 ft	Pickup replacement, light loads
56 to 60 in	9 to 10 ft	Contractors, mixed jobsite hauling
84 in	12 ft	DRW cab chassis, heavier payloads
102 to 120 in	14 to 16 ft	Long chassis, larger material runs

Term	One line meaning
Cab to axle (CA)	Back of cab to rear axle center
Wheelbase (WB)	Front axle center to rear axle center
Frame rail width	Outside to outside rail distance
Bed length	Listed body length, confirm definition
Deck length	Usable flat surface length
Overall length	Total body length including rear structure

Tools you need and where to put the tape

Use consistent reference points. Start at the back of cab wall, then measure to the rear axle centerline. Keep the tape straight along the truck centerline. A diagram style reference is here: wheelbase vs cab to axle. It helps confirm where each measurement starts and ends.

Tools

• Tape measure, 12 feet or longer.

• Phone camera for quick photos.

Step by step CA measurement (numbered steps)

Record CA in inches and repeat once. Keep both numbers in your notes. A short walkthrough is here: cab to axle measurement quick guide. Use it to confirm your tape placement before you send numbers.

1. Park on level ground and set the parking brake.

2. Mark the back of cab wall at a clear edge.

3. Find rear axle centerline using the hub center.

4. Measure from cab mark to axle centerline, straight and level.

5. Read inches, then repeat and record the second value.

Measure frame rail width and note key clearance points

CA picks bed length, but frame rail width affects mounting. Some frames taper, and some have tanks or brackets near mount zones. Measure rail width where the bed will sit, then note any clearance issues you spot.

Record these items

• Frame rail width outside to outside at mount area.

• Any taper points you can see near mounts.

• Fuel and DEF tank location, exhaust path, hitch layout.

Write these numbers down

• Cab to axle in inches.

• Frame rail width outside to outside.

• SRW or DRW, plus tire size if known.

• Towing type: bumper pull, gooseneck, or both.

Flatbed size chart by cab to axle

Charts beat guessing. A chart turns one CA value into a short list of bed lengths you can work with.

Common CA sizes and matching flatbed lengths

Many trucks fall into common CA ranges. Those ranges map to common bed lengths used in production builds. Two helpful references for cross checking are cab to axle and bed length chart and common cab to axle lengths by flatbed size. Use them as a quick sanity check, then confirm with your builder's drawing.

When to choose the shorter option vs longer option

Some CA values can fit two bed lengths. A shorter bed can help with ramp clearance and hitch access. A longer bed can add deck space for longer material, but you need a load plan that keeps weight balanced.

Flatbed width and configuration (SRW vs DRW)

Width choice affects tire clearance and load control. Too narrow reduces tie down options and deck space. Too wide can create tire rub or yard clearance issues in tight lots.

Single rear wheel width targets

SRW builds often target decks near 80 to 84 inches. Tire clearance through suspension travel matters more than a catalog number. Note spacers, wide tires, and any step changes at the fender.

Dual rear wheel width targets

DRW trucks often use decks near 96 to 102 inches. Confirm outside dual width and mud flap bracket space. Check route and yard clearance for the outside deck width.

Width warning

Confirm outside deck width against your routes and yards. Measure twice if you work tight lots and steep aprons.

Payload, axle ratings, and weight placement checks

Bed size must match axle ratings, not just frame length. Bed length can shift where cargo ends up on the deck.

GVWR and GAWR, what to check on the door tag

The door jamb label lists GVWR plus front and rear GAWR. Those numbers set the limits for your truck when loaded. Record the values and keep them with your build notes.

How bed length shifts load on the rear axle

Longer beds invite loads farther back on the deck. More rearward load can raise rear axle stress. Set a placement rule for heavy items and keep it consistent.

Fast checks before you buy

• Confirm bed weight and payload impact in the quote.

• Keep the heaviest items ahead of the rear axle centerline.

• Avoid dense loads at the tail when towing is common.

Towing and hitch clearance (gooseneck and bumper pull)

Towing clearance problems often appear after install. The bed fits the frame, but the trailer can contact the deck on turns.

Gooseneck neck clearance and deck cut options

Gooseneck towing needs space between trailer neck and the deck. Tight turns are where contact happens near the front of the deck. For bed style context, see Gooseneck flatbed vs standard flatbed. This section focuses on clearance and fitment numbers.

Gooseneck checks

• Ball location relative to back of cab.

• Neck height relative to deck surface.

• Turn clearance at full lock both directions.

Receiver and bumper space needs

Bumper pull towing needs clear receiver access. Rear overhang, steps, and light guards can block pins and plugs. Check hand clearance with gloves on and check chain hook space.

Accessories that change the "right" flatbed size

Add ons can change usable deck space and clearances. Toolboxes, racks, and rails can reduce working area near edges.

Front and side accessories that change usable deck

Racks take up front deck space. Toolboxes reduce usable width near the box location. Side rails can change access in tight yards. A guide on accessory ideas is here: Flatbed accessories that improve safety and productivity. Pick accessories first, then confirm your usable deck space.

Rear accessories that change clearance

Rear lighting and steps affect clearance at the tail. Mud flaps and brackets affect ramp clearance. Towing setups need clean access to receiver pins and plugs.

Compliance notes for width, lights, and state height limits

Rules vary by state and by route. A build that fits local runs may hit limits on highways or bridges.

Federal width baseline and what counts in the measurement

Measure outside deck width and outside rail width. Confirm rules for your route class and state. A baseline reference is here: Federal size regulations for commercial motor vehicles. Use it as a starting point, then confirm your state and route rules.

Lighting and height checks

Rear lights must stay visible with typical loads. Corner protection should not block light output. States set height limits, so record your tallest repeat load height.

Mistakes that cause wrong fitment

Fitment errors are common and easy to fix. Use this list as a final check before you place the order. It can save a rework visit.

Mixing trailer specs with truck mounted flatbed specs

Trailer specs often use different assumptions for length and width. Truck mounted flatbeds must match frame rails, axle placement, and rear clearance. Keep trailer sizing talk separate from truck bed fitment talk.

Guessing CA and ignoring frame width

Guessing CA can place the axle wrong under the deck. Ignoring frame rail width can force mount changes. Measure both and record the values in inches.

Forgetting rear overhang, bumper, and hitch space

Rear space can get tight after install. Steps, bumpers, and mud flaps can block hitch pins and plugs. Rear overhang can drag on ramps and driveways.

Mistakes and one line fixes

• Using trailer dimensions as a bed reference. Fix: Use CA and frame rail width for truck beds.

• Measuring to the tire edge. Fix: Measure to the rear axle centerline.

• Measuring CA once. Fix: Measure twice and record both values.

• Skipping frame taper checks. Fix: Measure rails at mount zones and near taper points.

• Locking width before SRW or DRW confirmation. Fix: Confirm rear wheel setup and outside tire width.

• Choosing length based on "more deck." Fix: Match CA, then plan load zones.

• Forgetting rear plug access. Fix: Check hand clearance at plug and receiver pin.

• Adding boxes without layout. Fix: Map box size and door swing on a simple sketch.

Size selection checklist you can hand to your upfitter

A checklist speeds up quoting and reduces follow up calls. Copy this section into an email and add photos.

Measurements to provide

Measurements should be in inches. Add a second check for CA and rail width. Photos help the shop confirm brackets and clearance zones.

Core measurements

• Cab to axle in inches.

• Frame rail width outside to outside at mount area.

• SRW or DRW, plus tire size if known.

• Desired bed length and target deck width.

Job use details that change size choice

Use details can change bed length choice with the same CA. Towing and storage can change rear clearance needs. Load length habits can change deck length needs.

Use details

• Typical loads and longest recurring load length.

• Towing type and trailer clearance needs.

• Loading method and storage plan.

Questions to ask before build day

Ask these during the quote stage. They confirm you and the shop are using the same definitions. They can prevent the "wrong length label" problem.

Questions

• Is the quoted length deck length or overall length?

• Where will the rear axle sit under the deck?

• Will the receiver and trailer plug stay accessible?

• What is the bed weight and payload impact?

Printable checklist

• Cab to axle: ____ in. Frame rail width: ____ in.

• Rear wheels: SRW or DRW. Tire size: _____.

• Desired bed: ____ ft long, ____ in wide.

• Towing: bumper pull, gooseneck, both, none.

• Accessories planned: boxes, rack, rails, steps, lights.

• Longest recurring load: ____ ft.

How Jutland helps confirm fitment without guesswork

A good match starts with your chassis numbers and your work needs. Clear measurement notes and photos can speed the match process.

What info to send for a fast match

Send CA, rail width, rear wheel setup, plus towing needs. Add photos of the rear frame, hitch area, and tank areas. Add your typical loads and the longest recurring load length.

For an overview, see Jutland flatbed bodies. For browsing, see Shop Jutland flatbeds.

Common size options and custom notes

Many buyers use standard lengths that match common CA ranges. Custom notes matter for rear steps, hitch access, and accessory layouts. For more context on feature sets, see Flatbed truck bodies: types, features, pricing. Use it to compare layouts once your size is locked.

When to choose aluminum for payload headroom (keep this brief)

Bed weight affects payload headroom on rated trucks. A lighter bed can leave more capacity for tools, cargo, and tongue load. A material overview is here: Aluminum vs steel flatbeds. Use it to compare weight and durability notes after fitment is confirmed.

FAQ

Quick answers help buyers who are quoting fast. These answers are short and can stand alone in search results. Use them as a final check before ordering.

What is cab to axle and why does it matter for bed length?

Cab to axle is back of cab to rear axle center. It maps directly to many flatbed length chart guides. Wrong CA can place the axle wrong under the deck.

How do I choose bed length from cab to axle?

Match your CA to a fitment table, then pick the length shown for your range. If CA sits near a break point, check overhang and towing clearance.

What is frame rail width and why measure it?

Frame rail width is outside to outside distance of the rails. It affects mounting points and spacer needs. Measure at the mount area and near any taper.

What flatbed width fits SRW trucks?

Many SRW builds use decks near 80 to 84 inches. Tire clearance matters more than a catalog number. Measure outside tire width and note spacers or wide tires.

What flatbed width fits DRW trucks?

Many DRW builds use decks near 96 to 102 inches. Confirm outside dual width and mud flap bracket space. Check yard and route clearance for the outside deck width.

How much rear overhang is acceptable?

Rear overhang must clear steep driveways and site ramps. Overhang should keep receiver pin and plug access usable. Check common jobsite entrances before choosing length.

What measurements matter most for gooseneck clearance?

Ball location and neck swing clearance matter most. Check turn clearance at full lock in both directions. Confirm rack height and front deck clearance zone.

What should I send an upfitter for a fast quote?

Send CA, frame rail width, SRW or DRW, and desired bed length and width. Add towing type, photos, and the longest recurring load length.

Wrap up

Most flatbed sizing problems come from skipping basic measurements. Cab to axle and frame rail width drive fitment, then the bed choice gets easier. When those numbers are right, you spend less time correcting the plan.

After that, width choice and rear clearance finish the job. SRW or DRW sets deck width targets, then towing needs shape the rear layout. A quick clearance check prevents hitch access issues later.

Before you order

• Measure cab to axle in inches, then measure it one more time.

• Measure frame rail width where the bed will mount on the chassis.

• Confirm SRW or DRW and note your rear tire size.

• Pick bed length from CA, then check rear overhang at ramps.

• Check receiver access, trailer plug access, and safety chain space.

• Plan accessory layout so boxes and racks do not steal deck space.

• Read GVWR and GAWR on the door tag and record both axle ratings.

• Keep a simple load placement rule for heavy items near the axle.

 

Final fitment must match the OEM chassis upfit guide and axle ratings. If you want a second set of eyes, reach out to Jutland for fitment help. Send your CA, frame rail width, SRW or DRW, towing type, and a few clear photos.