Fitment Guide
Find the Right Cap
Find the Right Cap
for Your Truck
Buying a used truck cap can save you thousands — but only if it actually fits your truck. Bed length, cab style, model year, and body generation all affect compatibility. This guide explains exactly what to check before you buy.
40–70%
Savings vs. New
01
Identify your truck
Know your exact year, make, model, and cab configuration before you start shopping.
02
Measure your bed
Measure inside from the front bulkhead to the closed tailgate. Never estimate by appearance.
03
Verify the generation
Truck redesigns change bed rail shape, rooflines, and tailgate dimensions — even within the same name.
04
Confirm before buying
When in doubt, contact our fitment team. We verify specs against the listing before you commit.
Why it matters
What’s at Stake with Bad Fitment
Weather Sealing
A poorly fitted cap lets in rain, dust, and moisture. Proper fitment ensures a tight seal against the bed rails and tailgate.
Tailgate Operation
The cap must clear the tailgate when it opens and closes. Wrong fitment can bind the tailgate or prevent it from opening at all.
Flush Appearance
A correctly fitted cap follows the truck’s body lines and sits flush with the bed rails. Gaps or overhangs are a sign of wrong fitment.
Structural Stability
Caps are clamped to the bed rails. If the cap doesn’t match, clamps can’t grip properly — creating a safety risk at highway speeds.
Window Alignment
Side windows and the rear window must align with the cab profile and tailgate. Misalignment prevents proper operation and sealing.
Long-Term Durability
A mismatched cap flexes, rattles, and stresses mounting points over time. Correct fitment means years of trouble-free use.
Step 2 — Measure your bed
Bed Length Reference
Measure the inside of your bed from the front wall to the inside of the closed tailgate. Never rely on the truck’s marketing name — always measure.
Short
Short Bed
- 5’5″
- 5’6″
- 5’7″
- 5’8″
Standard
Standard Bed
- 6’4″
- 6’5″
- 6’6″
Long
Long Bed
- 8’0″
Step 3 — Know your cab
Cab Configurations
Your cab style determines which bed lengths are available on your truck and affects overall fitment compatibility.
Regular Cab
Two doors, single row seating. Typically paired with standard or long bed options.
Extended Cab
Smaller rear doors with additional storage or jump seating. Commonly pairs with short or standard beds.
Crew Cab
Four full-size doors with full rear passenger seating. Most often paired with short or standard beds.
Cross-compatibility reference
What’s Usually Compatible
Often Compatible
Silverado & Sierra (same generation)
Chevrolet Silverado and GMC Sierra share body dimensions within the same generation. Caps typically interchange between these two brands.
Often Compatible
Colorado & Canyon (same generation)
The Chevrolet Colorado and GMC Canyon are platform-shared midsize trucks. Caps generally fit both when the generation and bed length match.
Sometimes Compatible
Different years, same generation
Minor model year updates within the same generation usually don’t affect cap fitment — but always verify before purchasing.
Sometimes Compatible
Different bed lengths, same truck
A short-bed cap will never fit a long-bed truck. Bed length must be an exact match. “Close enough” does not work with truck caps.
Rarely Compatible
Different truck generations
A redesigned body generation changes bed rail shape, roofline, and tailgate height. A 2013 F-150 cap almost never fits a 2021 F-150 correctly.
Rarely Compatible
Different manufacturers
Ford, Chevy, Ram, and Toyota all use different bed dimensions and rail heights. Caps are not interchangeable across brands in most cases.
What to avoid
Common Fitment Mistakes
Buying based on color alone
A cap can always be repainted. A cap that doesn’t fit cannot be forced to fit. Prioritize fitment first — color second.
Ignoring bed length
This is the most common mistake. The wrong bed length almost always results in a failed installation with no workaround.
Assuming all trucks of the same name match
Not all F-150s, Silverados, or Tacomas share identical dimensions. Generation changes and bed length variations make this assumption dangerous.
Skipping verification
Always confirm year, make, model, bed length, and cab style before purchasing. Our fitment team can verify any cap in our inventory for free.
Pre-purchase checklist
Confirm These 5 Things Before You Buy
Exact model year
Truck make
Truck model
Bed length (measured)
Cab configuration
What we carry
Popular Brands in Our Inventory
A.R.E.
Premium Fiberglass
LEER
Caps & Tonneau
SnugTop
Sleek Styling
Century
Commercial & Work
Ranch
Work & Personal
Why buy used
Benefits of Buying Used
Save 40–70%
Vs. buying new from a dealer
Premium Brands
A.R.E., LEER, SnugTop at lower prices
Faster Availability
No factory lead times or order waits
Less Depreciation
Used caps hold value better than new
Environmentally Responsible
One less cap manufactured or in a landfill
Nationwide Inventory
Thousands of listings updated daily
Free fitment help
Not Sure if It Fits?
We’ll Tell You.
We’ll Tell You.
Give us your year, make, model, and bed length and our fitment team will cross-reference our inventory and confirm compatibility before you spend a dollar.
Ready to find your cap?
Search by Make, Model
Search by Make, Model
& Bed Length
Browse thousands of verified used truck caps filtered to your exact truck. Save 40–70% compared to buying new — and get it installed this week.
