Measure the body and roots
Measure the widest body span, including spines if shelf clearance matters. Measure root-ball width and depth separately; never infer roots from the body.
DESERT PRECISION STUDIO / 01
Find the pot that fits.
Your cactus. Its perfect pot. Before you plant.
01 / CACTUS
Your cactus
Photo & growth scenario
Same proportions, one shared scale. Screen size is not life size.
02 / POT
Your pot
Clearance per side
Space below roots
New soil estimate
Optional screen calibration
Match the bar to an 85.6 mm wide card, then enable life size. Do not share card details.
03 / POT PASSPORT
Your Pot Passport
Keep the measurements behind your decision. Save this combination, share a link, or download a PNG card.
Geometric estimate · verify the physical pot before planting.
04 / FIELD NOTES
A little precision. A better fit.
Inside is what counts
Use outer dimensions for appearance. Measure the inner top and bottom diameters and the usable soil depth below the rim. Leave watering headspace before entering usable depth.
Look beyond the silhouette
Check drainage, pot stability and available shelf width. Aesthetic balance is personal. Dimensions alone cannot establish plant health or watering needs.
Practical potting notes
How big should my cactus pot be?
Start with the measured roots and check that they physically fit. This tool reports clearance instead of assigning a universal health score. Species, root condition, substrate and your growing conditions still matter.
Is a larger pot always better?
No. Unused soil can retain moisture. Compare several modest size changes and check drainage and drying conditions before deciding.
Terracotta or glazed ceramic?
Unglazed clay generally loses moisture more readily; glazed ceramic and plastic retain it longer. The palette here is visual only and does not model drying time. Use a container with drainage.
How is soil volume calculated?
The pot is approximated as a truncated cone: πh(D² + Dd + d²)/12. We subtract a cylindrical root ball. One cubic centimetre equals one millilitre. Irregular roots, taper, settling and stones change the real amount.
Is the preview actual size?
The default is a proportional preview. Life-size mode requires manual screen calibration against an 85.6 mm wide card. Recalibrate after zoom, screen or orientation changes; large objects may not fit.
Are my photos uploaded?
No. A selected image stays in your browser and is stretched to the entered body dimensions. Use a tightly cropped transparent PNG; automatic background removal is not provided.
Sources & method
Care references: Iowa State University Extension and University of Minnesota Extension. Geometry and illustrations are simplified planning aids, not species-specific prescriptions.
Iowa State: Growing Succulents Indoors ↗
University of Minnesota: Drainage & repotting ↗
About CACTUS FIT
An independent measuring and visual planning studio for cactus enthusiasts. Illustration presets describe shapes, not verified species measurements. No account is needed. Updated 26 October 2026.
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Privacy
Measurements remain in this browser unless you copy a setup link. Local saving uses browser storage. Photos are not included in shared links. Google/Blogger and existing advertising services may process cookies or usage data under their own policies.