Truck Cab to Axle (CA) Chart 2026: Body Length for Ford, Ram & GM Trucks
Quick answer: Cab-to-axle (CA) is the distance from the back of the cab to the center of the rear axle, and it sets how long a body you can mount. On a 2026 Ford Super Duty chassis cab, the 60-inch CA (145.3-inch wheelbase, Regular Cab) is listed for 8 to 9 ft bodies, the 84-inch (169.3 in) for 10 to 12 ft, the 108-inch (193.3 in) for 11 to 16 ft and the 120-inch (205.3 in) for 12 to 18 ft. A pickup has a much shorter CA: 27.2 inches on a 2026 F-150 SuperCrew with the 5.5-ft box.
We checked the numbers on this page in November 2026 against Ford Pro’s 2026 Body Builders Layout Books (Super Duty, F-150, F-650/F-750, E-Series and Transit), Ford’s 2022 Body Application Guide (body lengths by CA), Ram’s and Chevrolet’s own chassis cab specs, the NTEA truck equipment glossary, Knapheide’s cab-to-axle guide and Holman’s Body Selector (February 2026). Each table names its model year. Confirm your own chassis in its layout book or build data before you order a body.
2026 Ford Cab-to-Axle Chart at a Glance
| Ford chassis (2026) | CA options (inches) | Wheelbase (inches) |
|---|---|---|
| F-150 pickup | 27.2 (SuperCrew 5.5 ft), 39.1 (6.5 ft box), 57.7 (Regular Cab 8 ft) | 122.8–157.2 |
| F-250/F-350 pickup | 39.9 (6.75 ft box), 56.1 (8 ft box) | 141.6–176.0 |
| Super Duty chassis cab (F-350 to F-600) | 60, 84, 108, 120 | 145.3–205.3 |
| E-Series cutaway (E-350/E-450) | 80, 100, 118 | 138, 158, 176 |
| Transit chassis cab and cutaway | 82.5, 100.2, 122.2 | 138, 155.7, 178 |
| F-650/F-750 straight frame | 72 to 207 (up to 12 options per cab) | 158–281 |
Source: Ford Pro’s 2026 Body Builders Layout Books. Pickup CA is measured to the back of the cab with the box on. The chassis cab CAs are nominal: Ford Pro’s F-550 comparison sheet lists the 60-inch CA trucks at 59.6 to 59.7 inches.
What Is Cab-to-Axle (CA)?
The NTEA truck equipment glossary defines CA as “the distance from the back of the truck cab to the center of the rear axle.” On a tandem-axle truck, it runs to a point midway between the two rear axles. Ford’s layout books use the same definition: “back of cab to C/L of rear axle (CA).”
CA is measured to the back of the cab, not to anything mounted behind it. The NTEA notes that a “clear” or “effective” CA is measured from the rear surface of any obstruction behind the cab, which matters if a fuel tank, DEF tank or headache rack sits there. Knapheide’s cab-to-axle guide also lists fuel and DEF tank location among its compatibility checks.
| Term | Meaning | Why it matters |
|---|---|---|
| CA (cab to axle) | Back of cab to center of the rear axle | Sets the longest body that fits on a single rear axle |
| CT (cab to tandem) | Back of cab to the midpoint between the tandem axles (the trunnion) | The same job as CA on a tandem-axle truck |
| AF (after frame) | Center of the rear axle to the end of the frame | How much frame supports the rear of the body |
| WB (wheelbase) | Center of the front axle to center of the rear axle | Used for weight distribution and turning |
| CE (cab to end of frame) | Back of cab to the rear of the standard frame | Used mainly to size the body |
Sources: NTEA glossary for CA, CT and CE; Knapheide’s terms guide for AF and WB.
Cab-to-Axle Body Length Chart (Upfitter Guide)
This is the general chart upfitters use to match a body to a CA. It combines Knapheide’s cab-to-axle guide and Holman’s Body Selector (February 2026), which agree on the common sizes. Knapheide says its lengths are nominal, and Holman says its CA figures are only for estimating body length.
| CA (inches) | Service / utility body | Platform, flatbed or stake | Dump (single axle) | Listed by |
|---|---|---|---|---|
| 36–42 | 7 ft | 7 ft | – | Knapheide |
| 56 | 8 ft | 8 ft | – | Knapheide, Holman |
| 60 | 9 ft | 9 ft | 9 ft | Knapheide, Holman |
| 72 | – | 10 ft | – | Holman |
| 84 | 11 ft | 10, 11 or 12 ft | 11 ft | Knapheide, Holman |
| 102 | – | 13 ft | – | Holman |
| 108 | 13 ft | 13, 14 or 16 ft | – | Knapheide, Holman |
| 120 | 14 ft | 14, 16 or 18 ft | 14 ft | Knapheide; Holman (dump) |
| 138 | – | – | 16 ft | Holman |
Knapheide lists several platform lengths at 84, 108 and 120 inches, so one CA can cover a range of bodies. For tandem-axle dump trucks, Holman lists CT 84 inches for a 12 ft body, 102 for 13 ft 6 in, 108 for 14 ft and 120 for 15 ft. Holman adds that on a single-axle truck, CA plus 32 inches is the dump body hinge center, with no allowance for cab clearance.
Ford Super Duty Chassis Cab CA Chart (2026 F-350 to F-600)
From Ford’s 2026 Super Duty Body Builders Layout Book (chassis cab dimensional data), in inches. AF is the standard frame behind the rear axle.
| Cab | CA | Wheelbase | AF | Models |
|---|---|---|---|---|
| Regular Cab | 60 | 145.3 | 47.2 | F-350 SRW/DRW, F-450, F-550, F-600 |
| Regular Cab | 84 | 169.3 | 47.2 | F-350 DRW, F-450, F-550, F-600 |
| Regular Cab | 108 | 193.3 | 47.2 | F-450, F-550, F-600 |
| Regular Cab | 120 | 205.3 | 47.2 | F-450, F-550, F-600 |
| SuperCab | 60 | 167.9 | 47.2 | F-350, F-450, F-550 |
| SuperCab | 84 | 191.9 | 47.2 | F-450, F-550 |
| Crew Cab | 60 | 179.8 | 47.2 | F-350, F-450, F-550 |
| Crew Cab | 84 | 203.7 | 47.2 | F-450, F-550 |
The F-600 is Regular Cab only. On the F-450 to F-600 Regular Cab, Ford also lists frame extensions that lengthen the after-frame to 89.4 inches on the 60-inch CA and 79.6 inches on the 84-inch CA. The chassis cab frame is 34.2 inches wide at the rear axle, versus 37.7 inches on the pickup. Planning a Ford body? Our Super Duty wheelbase chart covers wheelbase by year, and the Super Duty payload chart covers the weight side.
Which body lengths Ford lists by CA
Ford’s 2022 Body Application Guide (its most recent public edition) marks which body type and length each chassis is intended for. The CAs are the same on the 2026 trucks. For the Regular Cab F-450, the chart reads:
| CA / wheelbase | Body lengths listed (stake/platform, dump, van or utility) |
|---|---|
| 60 / 145 | 8 ft and 9 ft stake/platform; 8 ft and 9 ft dump; 9 ft utility |
| 84 / 169 | 8 ft dump with back pack; 10 ft stake/platform, dump and van; 11 ft utility; 12 ft stake/platform and van |
| 108 / 193 | 11 ft utility; 12, 14 and 16 ft stake/platform and van |
| 120 / 205 | 12, 14, 16 and 18 ft stake/platform and van |
On the F-350, the 60-inch CA covers the same 8 and 9 ft bodies (the single rear wheel version lists no dump bodies), and the 169-inch wheelbase with the 84-inch CA lists 9 ft utility through 12 ft stake/platform and van.
Ford pickup CA: F-150 and F-250/F-350
Pickups have a CA too. It matters for a box-delete upfit, a flatbed swap or a fifth-wheel hitch. Ford lists it as “cab to C/L of rear axle” in each layout book:
| Truck | Cab and box | Wheelbase (in) | CA (in) |
|---|---|---|---|
| 2026 F-150 | Regular Cab, 6.5 ft | 122.8 | 39.1 |
| 2026 F-150 | Regular Cab, 8 ft | 141.4 | 57.7 |
| 2026 F-150 | SuperCab, 6.5 ft | 145.4 | 39.1 |
| 2026 F-150 | SuperCrew, 5.5 ft | 145.4 | 27.2 |
| 2026 F-150 | SuperCrew, 6.5 ft | 157.2 | 39.1 |
| 2026 F-150 Lightning | SuperCrew, 5.5 ft | 145.5 | 27.4 |
| 2015–2020 F-150 | SuperCrew, 5.5 ft | 145.0 | 26.8 |
| 2015–2020 F-150 | 6.5 ft box (Regular, SuperCab, SuperCrew) | 122.4 / 145.0 / 156.8 | 38.6 |
| 2015–2020 F-150 | 8 ft box (Regular, SuperCab) | 141.1 / 163.7 | 57.3 |
| 2026 F-250/F-350 | SuperCab or Crew Cab, 6.75 ft | 148.0 / 159.8 | 39.9 |
| 2026 F-250/F-350 | Regular, SuperCab or Crew Cab, 8 ft | 141.6 / 164.2 / 176.0 | 56.1 |
Sources: Ford Pro’s 2026 Body Builders Layout Books (F-150 and Super Duty) and Ford’s 2020 F-150 Body Builders Layout Book. The cab length doesn’t change CA on a pickup. The box length does. For older trucks, check that model year’s layout book on Ford Pro’s publications page. See our F-150 wheelbase chart and F-250 bed size chart for the matching wheelbase and bed specs.
F-650 and F-750 medium duty CA options (2026)
Ford’s medium-duty trucks offer far more CAs. The 2026 Medium Duty Body Builders Layout Book lists these for the straight-frame F-650 and F-750 (gas and diesel):
| Cab | CA options (inches) | Wheelbase range (in) |
|---|---|---|
| Regular Cab | 84, 102, 108, 120, 126, 138, 144, 150, 156, 168, 186, 207 | 158–281 |
| SuperCab | 84, 108, 120, 126, 144, 150, 156, 186 | 179–281 |
| Crew Cab | 72, 84, 102, 108, 120, 126, 136, 150, 156, 168 | 182–278 |
Not counting the 72-inch Crew Cab, that’s 29 combinations, which matches the “29 standard clean CA offerings ranging from 84 to 207 inches” on Ford’s F-650/F-750 page. The 207-inch CA uses the heavier 538 frame. The same book’s dimensional chart lists the 248-inch Crew Cab at 138 inches instead of 136, so confirm that one with Ford.
Ford E-Series Cutaway and Transit Chassis Cab CA
Cutaways and the Transit chassis cab have longer CAs for their wheelbase because the cab is short. These figures are from Ford’s 2026 E-Series and Transit layout books. The body lengths are the ones Ford tabulates for each wheelbase and CA in the weight-distribution chart of its 2022 Body Application Guide.
| Chassis (2026) | Wheelbase (in) | CA (in) | Body lengths Ford tabulates |
|---|---|---|---|
| E-350 cutaway (SRW or DRW) | 138 | 80.0 | 10–12 ft |
| E-350/E-450 cutaway | 158 | 100.0 | 11–16 ft |
| E-350/E-450 cutaway (DRW) | 176 | 118.0 | 14–16 ft |
| Transit T-250/T-350 chassis cab or cutaway | 138 | 82.5 | 9–12 ft |
| Transit T-250/T-350 chassis cab or cutaway | 155.7 | 100.2 | 10–14 ft |
| Transit T-350 HD DRW chassis cab or cutaway | 178 | 122.2 | 14–18 ft |
Ford’s 2022 guide listed the Transit CAs as 82.6, 100.3 and 122.6 inches. The 2026 drawings show 82.5, 100.2 and 122.2, so use the book for your model year. Ford Pro’s E-Series comparison sheet confirms 100 inches on the 158-inch and 118 inches on the 176-inch E-450. For cargo vans, see our Ford Transit cargo dimensions chart.
Ram 3500, 4500 and 5500 Chassis Cab CA
From Ram’s 2020 Chassis Cab Body Builder’s Guide (2020 model year, values as printed, same for the 6.4L and 6.7L engines). Ram’s 2026 chassis cab specs still offer the same CA choices: 60 or 84 inches on the 3500 Regular Cab and 60 on the Crew Cab, and 60, 84, 108 or 120 on the 4500/5500 Regular Cab and 60 or 84 on the Crew Cab. Check the current wheelbases in Ram’s body builder guide.
| Model | Cab | CA (in) | Wheelbase (in) |
|---|---|---|---|
| 3500 | Regular Cab | 60 | 143.5 |
| 3500 | Regular Cab | 84 | 167.5 |
| 3500 | Crew Cab | 60 | 172.4 |
| 4500 / 5500 | Regular Cab | 60 | 144.5 |
| 4500 / 5500 | Regular Cab | 84 | 168.5 |
| 4500 / 5500 | Regular Cab | 108 | 192.5 |
| 4500 / 5500 | Regular Cab | 120 | 204.5 |
| 4500 / 5500 | Crew Cab | 60 | 173.4 |
| 4500 / 5500 | Crew Cab | 84 | 197.4 |
Chevrolet Silverado 3500HD Chassis Cab CA
GM’s 2022 Silverado 3500 HD Chassis Cab brochure lists two Regular Cab chassis and one Crew Cab chassis. For 2026, Chevrolet’s chassis cab page lists “60-inch or 84.5-inch” CA on the Regular Cab and 60 inches on the Crew Cab.
| Cab | Wheelbase (in) | CA (in) |
|---|---|---|
| Regular Cab | 146.3 | 60.0 |
| Regular Cab | 170.8 | 84.0 (84.5 in Chevrolet’s 2026 specs) |
| Crew Cab | 176.7 | 60.0 |
We didn’t find a readable GM source for the 4500HD, 5500HD and 6500HD CA values, so they aren’t listed here. GM’s upfitter guides have them.
How to Match a Body to Your CA
A body that’s too long for the chassis puts its weight behind the rear axle and takes load off the front tires. Holman’s Body Selector gives a simple check: body center = CA − cab clearance − (body length ÷ 2), and the body center must be ahead of the rear axle centerline. The front axle’s share of the body weight is that distance divided by the wheelbase.
We applied it with the 2026 Super Duty wheelbases and a 3-inch gap between cab and body (Ford’s guide mentions a 3-inch allowance). These are our own worked examples for an evenly loaded body, not Ford figures.
| Body | CA / WB (inches) | Body center ahead of rear axle | Share of body weight on front axle | Fits Holman rule? |
|---|---|---|---|---|
| 9 ft | 60 / 145.3 | 3 in. | 2.1% | Yes |
| 12 ft | 84 / 169.3 | 9 in. | 5.3% | Yes |
| 14 ft | 108 / 193.3 | 21 in. | 10.9% | Yes |
| 16 ft | 120 / 205.3 | 21 in. | 10.2% | Yes |
| 12 ft | 60 / 145.3 | 15 in. behind | negative | No: needs 84-inch CA |
Real bodies are heavier at the front or rear depending on equipment, so this is only a first check. The body builder’s weight-distribution calculation and your chassis axle ratings decide. For payload limits, see our F-350 payload chart. For body weights, see how much a truck bed weighs.
How to Measure CA, AF and Wheelbase
- Park the truck on level ground with the wheels straight.
- Measure CA from the back of the cab to the center of the rear axle hub. If anything is mounted behind the cab, also measure from its rear surface to get the clear CA.
- On a tandem, measure to the midpoint between the two rear axles. That is CT.
- Measure AF from the center of the rear axle to the end of the frame rail.
- Measure wheelbase from the center of the front axle to the center of the rear axle.
- Compare your numbers with the build data or the maker’s body builder layout book, then give them to the body builder.
Body width matters as well as length on a dually. Our F-250 rear axle width chart has rear axle widths.
Frequently Asked Questions
What does cab-to-axle (CA) mean on a truck?
CA is the distance from the back of the cab to the center of the rear axle. On a tandem-axle truck, it is measured to the midpoint between the two rear axles, which upfitters call CT.
What is the CA on a Ford F-250 or F-350?
On a 2026 F-250/F-350 pickup, CA is 39.9 inches with the 6.75-ft box and 56.1 inches with the 8-ft box. The 2026 F-350 chassis cab is 60 inches on all cab styles, plus 84 inches on the 169.3-inch-wheelbase Regular Cab dually.
What is the cab-to-axle on an F-150 SuperCrew with the 5.5 ft bed?
Ford’s 2026 F-150 layout book lists 27.2 inches on the 145.4-inch-wheelbase SuperCrew with the 5.5-ft box (27.4 on the Lightning). The 2015–2020 F-150 SuperCrew 5.5 ft was 26.8 inches.
What body length fits a 60-inch CA?
Knapheide and Holman list 9 ft bodies for a 60-inch CA. Ford’s F-450 chart lists 8 and 9 ft stake, platform and dump bodies and a 9 ft utility body. A 12 ft body is too long for it.
What body length fits an 84-inch CA?
Ford’s F-450 chart lists 10 ft stake, platform, dump and van bodies, an 11 ft utility body and 12 ft stake, platform and van bodies on an 84-inch CA. Knapheide lists 10, 11 and 12 ft platforms and an 11 ft service or dump body.
What is the longest body for a 108 or 120-inch CA?
Ford lists up to 16 ft stake, platform and van bodies on the 108-inch CA and up to 18 ft on the 120-inch CA. Knapheide lists platforms of 13 to 16 ft at 108 inches and 14 to 18 ft at 120 inches.
What is the CA on a Ford E-Series cutaway or Transit chassis cab?
Per Ford’s 2026 layout books, the E-Series cutaway is 80 inches on the 138-inch wheelbase, 100 on the 158 and 118 on the 176. The Transit chassis cab and cutaway are 82.5, 100.2 and 122.2 inches on the 138, 156 and 178-inch wheelbases.
Related Ford Truck Guides
- Ford Super Duty Wheelbase Chart: All Years (1999–2026)
- Ford F-250 Wheelbase Chart
- Ford F-150 Wheelbase Chart
- Ford Truck Bed Size Chart
- Ford Super Duty Payload Capacity Chart
- Ford F-450 Towing Capacity
- Ford Transit Cargo Dimensions Chart
- How Much Does a Truck Bed Weigh?