Correct F-150 Tonneau Cover Fit by Generation and Bed Length
Table of Contents
Will your old F-150 tonneau cover fit a 2021 or newer bed?
Ford publishes identical cargo box dimensions for 2015–2020 and 2021+ F-150s. Many cover makers still sell separate part numbers for each generation, though. So the cover maker’s applicability list decides whether a cover is correct for your truck, not the tape measure alone.
Find your situation:
- Moving a cover to a newer truck: start with the part-number table below.
- Buying a used or discounted cover labeled for the other generation: read the traps section before you pay.
- Shopping for a truck you haven’t bought yet: the dimension table and cover-type comparison come first.
For every other F-150 specification, see our F-150 specs by configuration reference.
📍 Check your own vehicle first: Specifications vary by build date, package and market, and two trucks with the same badge can be built differently. Before you buy anything based on this page, confirm your box length on your window sticker or VIN build data, and confirm the cover’s applicability on the maker’s current installation sheet. If your vehicle disagrees with this page, your vehicle is right.
F-150 bed dimensions, 2015–2020 vs 2021+, in inches
Ford’s own specification sheets list the same box lengths for both generations.
| Ford box size | Inside length at floor | Length at top | Rear opening width | Applies To |
|---|---|---|---|---|
| 5.5 ft | 67.1 in | 65.4 in | 60.3 in | 2015–2020 and 2021+ F-150 Styleside |
| 6.5 ft | 78.9 in | 77.2 in | 60.3 in | 2015–2020 and 2021+ F-150 Styleside |
| 8.0 ft | 97.6 in | 95.9 in | 60.3 in | 2015–2020 and 2021+ F-150 Styleside |
Sources: Ford 2020 and 2021 F-150 technical specifications (floor length); Ford 2020 and 2022 dealer specification data (length at top, rear opening). Box availability depends on cab style.
📐 On the Spec Sheet: Ford’s 2020 F-150 technical specifications and 2021 F-150 technical specifications both list inside floor lengths of 67.1, 78.9 and 97.6 inches.
5.5 ft, 5’7″, or 5.6 ft: why the same bed has three names
Ford’s box names are nominal sizes, and cover makers relabel the same box in inches.
A 67.1-inch floor length works out to 5 feet 7.1 inches. That’s why many cover makers sell “5’7″ bed” covers for what Ford calls the 5.5-ft box. Likewise, 78.9 inches rounds to the “6’7″” label used for Ford’s 6.5-ft box.
Some sellers go further, listing this bed as 5.6 ft or even 5’5″ (66″).
🔍 What This Spec Means: The label on the box is marketing. The inch figure is the specification. Match the inch figure the maker lists to Ford’s 67.1, 78.9 or 97.6 inches.
🚫 Fits But Shouldn’t: A cover labeled only “5.5 ft” with no inch figure or F-150 model listed may be sized for a different truck’s short bed. Without Ford’s 67.1-inch figure and “F-150” in the maker’s applicability line, the label alone proves nothing.
Cab-by-cab box pairings are covered in our breakdown of F-150 bed dimensions in real inches.
Which cover part numbers cross between generations
Makers handle the 2021 generation change in one of two ways: they split part numbers, or they list one part across both generations.
| Maker / model | 2015–2020 part | 2021+ part | Applies To | Status |
|---|---|---|---|---|
| BAKFlip MX4 (hard folding) | 448329 | 448339 | 5’7″ (67.1″) bed; 2021+ listing includes Raptor and Lightning | Split by generation |
| TruXedo Sentry (hard rolling) | 1598301 | 1598301 | 6’7″ (78.9″) bed | One part across both generations |
A split part number doesn’t prove the beds differ. It means the maker hasn’t listed the older part for your model year. Fitting it anyway puts the cover outside that maker’s stated applicability.
⚠️ Watch Out: Retail listings for the same TruXedo part disagree on the end year, with ranges from 2015–2018 up to 2015–2026. Trust the maker’s current installation sheet, not the store’s listing.
What can stop a matching cover from fitting your truck
Matching box lengths is necessary, but three truck-side variables can still block a fit.
- Tailgate type. The Pro Access tailgate arrived with the 2024 refresh as an option on some trims and standard on others. Check whether the cover’s tailgate seal is listed as compatible.
- Liners and bed accessories. One maker notes that bedliner modification may be needed on some setups. Toolboxes or tall dividers can also block a cover.
- Raptor and Lightning. BAK lists its 2021+ MX4 for Raptor and Lightning, but applicability for these variants varies by maker and model.
Cover types and how forgiving each is across generations
Mount style determines how much a cover depends on exact rail geometry.
- Soft roll-up and soft folding: use clamp-on side rails. These generally tolerate small bed variations.
- Hard folding and hard rolling: designed to sit flush with the bed rails, so they depend more on exact rail dimensions.
- One-piece covers shaped to the box’s outer edges: depend on exterior body shape. Ford’s box dimensions don’t publish that shape, so these covers depend most on the exact generation.
A hard cover’s weight counts toward payload. See the F-150 payload capacity chart.
Check these three things before you buy or move a cover
Three checks settle almost every cross-generation cover question.
- Measure the box. Measure the inside floor length from the bulkhead to the inside of the closed tailgate, and compare it to 67.1, 78.9 or 97.6 inches.
- Confirm box and tailgate. Check your window sticker or VIN build data for box length and tailgate type.
- Read the applicability line. Find the maker’s current installation sheet and check that it lists your model year, box length and tailgate.
✅ Do This: Before buying a used cover, ask the seller for the part number printed on the cover or its rails. Then look that number up on the maker’s installation sheet.
FAQ
1. Is a 5’7″ tonneau cover the same as a 5.5-ft F-150 bed?
Yes. A 5’7″ tonneau cover label refers to Ford’s 5.5-ft box, which measures 67.1 inches at the floor.
2. Did the F-150 bed change size in 2021?
No. Ford lists the same 67.1-, 78.9- and 97.6-inch floor lengths for both 2015–2020 and 2021+ F-150 tonneau cover fit comparisons.
3. Will a BAKFlip MX4 from a 2018 F-150 fit a 2022?
BAK sells separate MX4 tonneau cover part numbers by generation, 448329 and 448339, so check BAK’s installation sheet before moving it.
4. Does the TruXedo Sentry fit both generations?
The TruXedo Sentry tonneau cover 1598301 is listed across both generations for the 78.9-inch bed, but retail listings disagree on end years.
5. Do 2021+ Raptor trucks take the same tonneau cover?
BAK lists its 2021+ MX4 tonneau cover for Raptor. Other makers vary, so confirm Raptor on the installation sheet.
6. Does the Pro Access tailgate affect tonneau cover fit?
It can. Check that the tonneau cover’s tailgate seal is listed as compatible with Pro Access tailgates before buying.
7. How do I measure my F-150 bed for a tonneau cover?
Measure the inside floor length from the bulkhead to the closed tailgate, then match it to 67.1, 78.9 or 97.6 inches.
8. Can a bedliner stop a tonneau cover from fitting?
Yes. Some makers note bedliner modification may be needed, so check your liner against the tonneau cover’s installation notes.
9. Why do tonneau cover listings show different model years for one part?
Retail listings for the same tonneau cover part can drift. The maker’s current installation sheet is the document that decides.
10. Is a used 2015–2020 tonneau cover safe to buy for a 2021+ truck?
Only if the maker lists that tonneau cover part for your year. Check the part number against the installation sheet first.
Before you buy: the one document that decides
Ford’s published box dimensions match across the 2021 changeover, but cover part numbers often don’t. The deciding document is the maker’s current installation sheet: it must name your model year, box length in inches, and tailgate type. Measure your truck, check your build data, and match all three before you spend.
