Inputs
Example Data Table
Sample scenarios to sanity-check your inputs and expectations.
| Crop | Area | Spacing (row × plant) | Survival | Yield basis | Estimated net yield |
|---|---|---|---|---|---|
| Tomato | 100 m² | 0.75 m × 0.45 m | 92% | 2.5 kg/plant | ~650 kg (after 5% non-crop, 5% losses) |
| Lettuce | 0.05 ha | 0.30 m × 0.30 m | 90% | 3.5 kg/m² | ~1,450 kg (single harvest, 4% losses) |
| Potato | 0.25 acre | 0.80 m × 0.25 m | 95% | 2.8 kg/m² | ~2,400 kg (10% non-crop, 6% losses) |
Formula Used
- Effective planted area: Aeff = A × (1 − nonCrop%/100)
- Plant density (area + spacing): density = 1 / (rowSpacing × plantSpacing)
- Total plants: plants = Aeff × density or, in rows mode: rows = ⌊width/rowSpacing⌋, plantsRow = ⌊length/plantSpacing⌋, plants = rows × plantsRow
- Surviving plants: plantssurvive = plants × (survival%/100)
- Gross harvest (per harvest): gross = plantssurvive × yieldPerPlant or: gross = Aeff × yieldPerM²
- Multi-harvest adjustment: grossTotal = gross × harvestCycles
- Loss adjustments: net = grossTotal × (1 − harvestLoss%/100) × (1 − postLoss%/100) Dry estimate: dry = net × (dryMatter%/100)
How to Use This Calculator
- Choose Area + spacing for quick plot estimates.
- Choose Rows + field dimensions if you know length and width.
- Enter row and plant spacing in meters, then set non-crop area.
- Set survival rate using your seed or transplant history.
- Pick a yield basis and fill the matching yield value.
- Add harvest cycles and realistic loss percentages.
- Click Estimate Yield, then export CSV or PDF.
Tip: If your output looks too high, increase non-crop area or losses, or reduce survival and yield rates.
Area and Plant Density
This calculator converts your plot size into planted area by subtracting paths and headlands. Many beds lose 3–15% to access lanes and edging. Plant density is estimated from row spacing and plant spacing. For example, 0.75 m by 0.45 m spacing gives about 2.96 plants per m², or roughly 296 plants per 100 m² before deductions. Tight greens at 0.30 m by 0.30 m can exceed 11 plants per m².
Survival and Stand Establishment
Not every seedling reaches harvest. Use survival rate to reflect germination, transplant shock, pests, and heat stress. Small gardens often see 85–98% survival with healthy starts, while direct-seeded beds may drop to 70–90%. If you expect replanting, lower survival to keep totals realistic. Surviving plants drive the per-plant yield option.
Yield Basis Selection
Choose per plant when you track average fruit or tuber weight per plant per harvest. Choose per m² when yield is measured by bed area, common for leafy greens and herbs. Enter realistic values, then multiply by harvest cycles for multi-pick crops like beans, tomatoes, and peppers. If you harvest weekly for 8 weeks, set cycles to 8 and use a per-harvest yield rate, not a seasonal total.
Loss Factors and Marketable Yield
Harvest loss covers unpicked produce, field damage, and grading discards; 2–10% is typical in harvests, and 10–20% is common when harvest timing slips. Post-harvest loss includes trimming, bruising, storage shrink, and transport, often 1–8%. Net usable yield equals gross yield multiplied by both loss adjustments. Use dry matter when planning dehydration; many vegetables fall between 5% and 15%, while grains and cured onions can exceed 85%.
Benchmarking and Record Keeping
Use the example table to compare your estimate with past seasons. Track inputs such as spacing, survival, and cycles, then update yield rates after each harvest. Reporting net kg/ha and kg/acre helps compare beds and varieties across different plot sizes. When you export reports, keep one file per crop and season to build a benchmark library.
FAQs
Which estimation mode should I choose?
Use Area + spacing when you only know total plot area. Use Rows + field dimensions when beds are rectangular and you know length and width; it counts whole rows and plants per row from spacing.
What does non-crop area represent?
Non-crop area is space not planted, such as paths, borders, irrigation lines, and turning zones. Enter a percent to reduce planted area so plant counts and yield stay realistic.
How do I estimate yield per plant?
Record a few harvests, then divide total harvested weight by the number of productive plants. Use an average per harvest, and set harvest cycles to the number of picks you expect.
When should I use yield per square meter?
Use per m² for crops harvested by bed area, like lettuce, spinach, and herbs, or when you have reliable yield trials per area. It is also useful when plant counts are uncertain.
Why do I need harvest and post-harvest losses?
Loss factors convert gross production into marketable or usable yield. Harvest loss covers field damage and missed picks. Post-harvest loss covers trimming, bruising, moisture loss, and spoilage in storage.
What is the dry matter option used for?
Dry matter estimates a dry-weight equivalent from net yield. It helps plan dehydration, curing, or milling. Enter a realistic percentage for your crop; if unknown, leave it at zero for fresh yield only.