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How To Measure For A Hot Tub Cover

a man trying to measure for a hot tub coverHero Image for How to Measure a Hot Tub Cover: Never Make a Costly Mistake Againhot tub cover

Why Accurate Hot Tub Cover Measurements Matter

Energy efficiency and cost savings

properly measured coverBosch BLAZE GLM 20Do’s and Don’ts for Energy Efficiency

DoDon’t
Measure the actual hot tub shell, not the old coverGuess measurements or round to nearest inch
Add proper overlap for the skirt (2-3 inches typically)Ignore corner radius measurements
Ensure the cover sits flat with no gapsUse a warped old cover as your measurement guide

Preventing water and chemical loss

chemical balanceStarrett Combination Square Set

Tools You’ll Need to Measure a Hot Tub Cover

  1. Digital Tape Measure – The Bosch BLAZE GLM 20 ($49.99) is a game-changer with its 1/16 inch accuracy! Those tiny hot tub dimensions won’t stand a chance. Plus, its backlit display is perfect for evening measuring sessions when your outdoor spa area isn’t exactly bathed in light.
    FeatureBenefit
    Digital precisionEliminates human error in reading measurements
    Memory functionStores measurements for easy reference
    Compact sizeEasily maneuvers around hot tub corners
    Weather resistanceSuitable for outdoor use in various conditions
  2. Flexible Measuring Tape – Grab the Stanley PowerLock 25-Foot Tape Measure ($12.97) for those curvy spots! It stays rigid when extended so you can tackle those measurements solo – no need to recruit a reluctant family member to hold the other end!
  3. Radius Measuring Templates – The Starrett Radius Gage Set ($19.95) is like having corner-measuring superpowers! These templates take all the guesswork out of figuring out exactly how curvy your hot tub corners really are.
  4. Notepad and Pencil – Simple but mighty! The weatherproof Rite in the Rain All-Weather Notebook ($8.95) laughs in the face of splashes and humidity. Your measurements stay safe even when surrounded by water!

Pro Tip

Why a carpenter’s square is essential

Do’s and Don’ts of Using a Carpenter’s Square

DoDon’t
Position the square flush against cornersEstimate corner measurements without proper tools
Use both inside and outside edges for different measurementsRely solely on tape measures for corners
Mark measurement points directly on the square temporarilyBend flexible measuring tapes around corners
Verify measurements multiple timesRush through the corner measurement process
  1. Perfect 90-degree reference – Is that corner truly square or slightly rounded? Now you’ll know for sure!
  2. Corner radius measurement – Just slide paper under the curve, trace along the edge, and voilà – exact corner curve captured!
  3. Skirt depth precision – That little depth ruler attachment perfectly measures how far down your cover should hang
  4. Template creation – Creating patterns for uniquely-shaped tubs becomes child’s play with perfect right angles

Step-by-Step Guide: How to Measure for a Hot Tub Cover

Step 1: Measure the length and width

  1. Stretch your tape measure across the top of your spa, from lip to lip
  2. Always measure from outside edge to outside edge (that’s the widest part!)
  3. Jot down those numbers to the nearest ⅛ inch (precision matters here!)
  4. Double-check yourself by measuring again (trust but verify!)

Pro tip

Step 2: Measure the corner radius

  1. Place your carpenter’s square snugly against the corner
  2. Slip a piece of paper underneath where the curve begins
  3. Trace along that curved edge onto your paper
  4. Measure from the square’s corner to where your traced line intersects

Step 3: Measure the skirt length

  1. Hold your tape measure vertically starting at the top lip of your hot tub
  2. Extend downward to where you want the cover to end (usually 2-3 inches does the trick)
  3. Write down each side separately – sometimes they’re not all the same!

Step 4: Measure the safety straps

  1. Measure how far apart the straps sit (usually on opposite sides)
  2. Note where the strap anchors attach to your hot tub cabinet
  3. Determine ideal strap length for easy buckling without stretching or sagging

Step 5: Add buffer space for shrinkage

  1. Add ¼ inch to both length and width measurements for vinyl covers
  2. For those uniquely-shaped tubs, add a generous ½ inch for manufacturing wiggle room
  3. Keep these final buffered measurements handy when ordering

Do’s and Don’ts Table for Measuring

DoDon’t
Measure the actual tub, not the old coverRound measurements to nearest inch
Take multiple measurements for verificationAssume all corners have same radius
Measure at the widest pointsGuess the skirt length
Account for material shrinkageMeasure a warped old cover
Use proper measuring toolsIgnore slight variations in shape
Photograph your measurement processRush through measurements

When to Measure the Tub vs. the Old Cover

Pros and cons of each method

Pros and Cons of Measurement Methods

Method

  • Measuring the Hot Tub
  • Measuring the Old Cover

Pros

  • • Most accurate dimensions• Accounts for true shell design• Eliminates accumulated errors
  • • Quicker process• Shows exact size that previously fit• Easier to trace unusual shapes

Signs your old cover is unreliable

Do’s and Don’ts for Evaluating Your Old Cover

DoDon’t
Compare old cover measurements with actual tubRely solely on visibly damaged covers
Check for symmetry across all dimensionsAssume minor sagging won’t affect measurements
Examine corner radii for distortionUse covers older than 3-5 years as templates
Verify straight edges are truly straightIgnore discoloration patterns that indicate warping
  1. Water pooling – See little puddle parties forming on top? That’s a sure sign of structural collapse underneath
  2. Uneven edges – Notice gaps when placed on the tub? Your cover has likely shrunk or warped
  3. Material discoloration – Spotty fading patterns aren’t just a fashion statement – they signal uneven exposure and distortion
  4. Visible cracks – Especially along those fold lines – they’re basically neon signs saying “internal breakdown here!”
  5. Surprising heaviness – If your once-light cover now feels like you’re lifting a small car, water-logged foam cores are changing its dimensions

Troubleshooting Common Measurement Mistakes

What to do if your cover doesn’t fit

  1. Confirm your measurements – Dust off those original notes and double-check every number
  2. Identify the specific fitting issue – Too big? Too small? Corner curves all wrong?
  3. Contact the manufacturer – Many offer adjustment options if you reach out within 30 days
  4. Document the problems – Snap clear photos showing those gaps or awkward overlaps

Do’s and Don’ts for Handling Ill-Fitting Covers

DoDon’t
Take detailed photos of fitting issuesAttempt to force an ill-fitting cover
Keep all original packagingTrim the cover yourself without expert guidance
Contact manufacturer immediatelyAssume minor fit issues will resolve themselves
Request adjustment guidelinesDiscard your measurement notes

How to fix incorrect radius measurements

  1. Grab the OLFA 18mm Fiberglass-Reinforced Utility Knife ($14.99) for careful corner rounding
  2. Make a template using cardboard pressed against your actual tub corner
  3. Mark your cutting lines precisely—measure twice, cut once!
  4. Smooth those freshly cut edges with fine-grit sandpaper
  1. Sadly, you can’t magically add material where there isn’t any
  2. Corner caps or custom foam inserts can fill those annoying gaps
  3. The Frost King Vinyl Foam Weather-Seal ($7.97) makes a great temporary fix

Final Thoughts – Never Make a Costly Hot Tub Cover Mistake Again!

FAQs

Q1. How important is an exact fit for a hot tub cover?Q2. What measurements do I need to take for a hot tub cover?Q3. How do I measure the corner radius of my hot tub?Q4. What’s the best way to measure an irregularly shaped hot tub?Q5. Should I measure my old cover or the hot tub itself?

Relaxing hot tub scene illustrating hot tub folliculitis prevention tips and safe maintenance practices for owners.

Article by Dave King

Hey, I’m Dave. I started this blog because I’m all about hot tubs. What began as a backyard project turned into a real passion. Now I share tips, reviews, and everything I’ve learned to help others enjoy the hot tub life, too. Simple as that.