Count slats fast for tidy greenhouse shading plans. Tune overlap, rails, and stack allowances. Export results for accurate gardening builds.
| Blind width (mm) | Blind drop (mm) | Pitch (mm) | Overlap (mm) | Allowances total (mm) | Waste (%) | Slats (with waste) |
|---|---|---|---|---|---|---|
| 1000 | 1200 | 22 | 2 | 140 | 3 | 56 |
| 1200 | 1500 | 25 | 2 | 145 | 5 | 58 |
| 900 | 1800 | 22 | 3 | 160 | 3 | 86 |
These examples assume rounding up and typical rail + stack allowances.
The calculator estimates how many slats fit in the usable drop.
For garden rooms, overlap helps block harsh afternoon light on seedlings.
Venetian blinds can help manage sun stress in indoor grow areas and seed-starting racks. This calculator estimates the slat count needed to cover a target drop with allowances for fit.
Excess light can scorch tender leaves, while low light slows seedlings. A correct slat count supports predictable shading bands so you can repeat the same settings across shelves. Consistent coverage also reduces temperature swings near glazing.
Pitch is the vertical distance each slat consumes when the blind is closed. Overlap subtracts from pitch, increasing slat density and improving glare blocking. In humid garden rooms, material flex can change closure behavior, so overlap provides margin.
Headrail, bottom rail, and stack allowance reduce the usable drop available for slats. If you ignore these, the calculated slats may exceed the available height and the blind will not seat properly. Measure the exact rail profiles for reliable counts.
A small waste percentage adds spare slats for trimming, edge damage, or later swaps. For DIY garden projects, 3–7% is common, especially when you cut slats to fit nonstandard window widths. The CSV export keeps a clean shopping list.
The tool reports a base count, a final count with waste, and estimated total slat length. Total length helps you compare pack sizes and plan inventory. Pair results with your slat width and finish for durable, clean surfaces.
Use the manufacturer’s closed-pitch value for your slat width. If you are unsure, measure a short test stack: close 10 slats, measure total height, and divide by 10.
Increase overlap when you see light leaks between slats, when cords pull slats slightly out of plane, or when humidity causes warping. Small increases often improve shading without changing hardware.
Raise the blind fully and measure the stacked height of the slats plus lift mechanism. Add a small buffer for clearance. Taller blinds typically need more stack allowance.
Rounding up prevents gaps at the bottom edge after installation and seasonal movement. A slight excess is easier to accommodate than a shortage, especially on bright-facing greenhouse panels.
Yes. Switch units to inches and enter all measurements in inches. The calculator converts internally and returns outputs in the same unit system for easy comparison.
Total slat length estimates how much slat material you need across the blind width. It’s useful for ordering bulk packs, planning spares, and comparing costs across suppliers.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.