| Scenario | Method | Coverage (W×L) | Roll width | Overlap | Waste | Strips | Total length (m) | Total area (m2) |
|---|---|---|---|---|---|---|---|---|
| Seedling bench | Bench | 64×124 cm | 100 cm | 1 cm | 5% | 1 | 1.30 | 1.30 |
| Wide propagation tray | Bench | 122×62 cm | 100 cm | 2 cm | 8% | 2 | 1.34 | 2.68 |
| Pot grid | Pots | 74×52 cm | 50 cm | 1 cm | 6% | 2 | 1.10 | 0.55 |
Use your own measurements for accurate totals.
- CoverageWidth = BaseWidth + 2×SideMargin
- CoverageLength = BaseLength + 2×EndMargin
- EffectiveStripWidth = RollWidth − SeamOverlap
- Strips = ceil(CoverageWidth ÷ EffectiveStripWidth)
- RawTotalLength = CoverageLength × Strips × Count
- RawTotalArea = RawTotalLength × RollWidth
- TotalsWithWaste = RawTotals × (1 + Waste%/100)
- WaterHeld = Area(cm2) × ml/cm2 ÷ 1000 → liters
- Select Bench coverage for trays/benches, or Pot layout for loose pots.
- Enter your dimensions and how many benches/setups you will cover.
- Set margins to protect edges and improve wetting consistency.
- Enter the roll width and overlap if you will join strips.
- Add a waste percentage for trimming and future repairs.
- Press Calculate to see strips, total length, and area.
- Use Download CSV or Download PDF after results appear.
Accurate mat sizing improves uniform moisture
Capillary mats work best when the wetted surface matches your growing footprint. Oversized mats curl, channel water, and invite algae on exposed edges. Undersized mats leave dry zones that slow germination and create uneven growth. This calculator converts your bench or pot layout into a practical coverage rectangle, then builds a cut plan based on roll width and seam overlap.
Margins, overlaps, and waste control real-world fit
Side and end margins protect the mat from shifting when trays are moved, fans run, or irrigation pulses start and stop. When coverage width exceeds roll width, joining strips is common; overlap reduces capillary breaks between strips. Waste percentage accounts for trimming corners, cutting around bench legs, and keeping a spare strip for quick repairs.
Roll width selection and strip planning
Wider rolls reduce seam count and speed installation, while narrower rolls can be easier to handle in tight benches. The calculator uses an effective strip width (roll width minus overlap) to estimate the number of strips required. Fewer seams generally means better wetting uniformity and less maintenance, but always confirm that your roll width fits your storage and cutting space.
Water holding estimate supports irrigation decisions
Water holding varies by mat thickness, fiber blend, and compaction. The absorption rate input (ml per cm2) lets you approximate how much water a fully saturated mat can store. Use it to compare scenarios, not as a laboratory value. If your trays feel too wet, reduce saturation time, increase airflow, or lower the absorption input to reflect your mat’s behavior.
Maintenance, hygiene, and replacement planning
Keep mats flat, flush salts periodically, and avoid standing nutrient solution for long periods. Algae growth usually indicates excess light on wet fabric; improve edge coverage or use light-blocking trays. Replace mats when wicking becomes patchy, odors persist after cleaning, or fibers shed into media. Use consistent sizing across benches to standardize watering and simplify reorders.
| Setup | Base size | Margins | Roll | Overlap | Waste |
|---|---|---|---|---|---|
| Bench A | 120×60 cm | 2 cm each side/end | 100 cm | 1 cm | 5% |
| Bench B | 180×75 cm | 3 cm each side/end | 100 cm | 2 cm | 8% |
| Pot grid | 6×4 pots (10 cm) + 2 cm gaps | 2 cm each side/end | 50 cm | 1 cm | 6% |
FAQs
1) Should the mat be larger than the bench?
Usually yes, by a small margin. A 1–3 cm margin per edge helps alignment and keeps capillary contact consistent when trays move. Avoid large exposed borders that stay wet and grow algae.
2) How much seam overlap is enough?
Use 1–3 cm for most joins. Overlap should maintain wicking continuity without creating a thick ridge that lifts trays. If you see dry lines at seams, increase overlap slightly and re-wet evenly.
3) When should I use Pot layout instead of Bench coverage?
Use Pot layout when pots sit directly on the mat without trays and spacing defines the footprint. Use Bench coverage for trays, flats, or when your bench dimensions are the controlling size.
4) What waste percentage is realistic?
Five percent suits straight benches and careful cutting. Use 8–12% for many seams, obstacles, or frequent changes. Add extra if you want a spare strip for fast patching during peak propagation.
5) How do I choose the absorption rate input?
Start with 0.4–0.8 ml/cm2. Thicker, denser mats hold more. If your mat dries faster than expected, lower the value. If it stays saturated too long, reduce it and shorten soak times.
6) How can I prevent algae on capillary mats?
Minimize exposed wet fabric, block light at edges, and avoid constant standing water. Periodic flushing and improved airflow help. Clean between cycles and let mats dry when possible to slow algae growth.
7) Do I need to replace mats on a schedule?
Replace when wicking becomes uneven, seams fail, or cleaning no longer removes odors and biofilm. Many growers refresh mats seasonally in heavy use. Track performance per bench and standardize replacements.