Vegetable Yield Calculator
Enter your crop type and bed size to instantly estimate total harvest weight, retail value, number of servings, and how many plants fit the space. Switch between metric and imperial, adjust your cost inputs to see whether growing your own beats the supermarket price, and use the seasonal harvest chart to plan picking over the growing season.
How vegetable yields are calculated
The calculator starts with a published average yield rate for the selected crop in kilograms per square metre of planted bed. That figure comes from research by the USDA and the University of California Cooperative Extension, which reports yields under typical home-garden conditions with adequate water, good soil, and routine pest management. The rate is multiplied by your bed area and by the number of successive sowing cycles you enter, since fast crops like lettuce, radishes, and spinach can be replanted two to four times in a single growing season. The usable-yield percentage (default 85%) then trims the total to account for produce lost to pests, disease, or simple over-ripening before it reaches the kitchen.
Retail value and net savings
To estimate what the harvest is worth, the calculator multiplies your usable yield in kilograms by the retail price per kilogram. If you leave the price field at zero, the calculator uses a built-in average based on USDA retail data for common vegetables. Enter your local supermarket price to get a more accurate figure. The net savings number then subtracts your season costs (seeds, compost, water, containers) from the harvest value. A positive result means the garden paid for itself; a negative result does not mean gardening is pointless, because many households grow varieties not found in shops and value the freshness and activity as much as the savings.
Plants and spacing
The plants-needed output divides the bed area by the recommended spacing density for that crop. Spacing standards follow intensive or raised-bed planting rather than the wider rows used in commercial production, so they reflect the spacing used in most backyard and community gardens. Crops like tomatoes, cucumbers, and squash need generous spacing because they spread or need support, so a 50 sq ft (4.6 sq m) bed fits only two or three plants. Lettuce, radishes, and carrots fit many more plants into the same footprint, which is why their yield per square foot compares favourably with larger crops. Correct spacing matters because overcrowded plants compete for light, water, and nutrients and typically produce less than plants grown at the right density.
Successive sowings and extending the harvest
Setting the "successive sowing cycles" field above 1 multiplies total yield for crops that complete their life cycle quickly enough to be replanted in the same season. A standard 8-week lettuce crop can be seeded again immediately after harvest, giving you two full yields in a 16-week growing season, and three or four cycles in warmer climates or under row covers. The seasonal harvest chart shows how this plays out week by week, with peak picking periods for each cycle clearly visible. Crops like tomatoes, peppers, and winter squash should stay at 1 cycle, because they occupy the bed for the entire season and cannot be succeeded in the same space.
Average vegetable yields and typical retail prices
| Vegetable | Yield (kg/sq m) | Plants per sq m | Retail price (USD/kg) | Typical serving (g) |
|---|---|---|---|---|
| Tomatoes | 8.0 | 0.5 | $3.30 | 150 |
| Cucumbers | 5.5 | 0.5 | $2.20 | 120 |
| Zucchini | 6.5 | 0.5 | $2.00 | 200 |
| Peppers | 4.0 | 0.7 | $4.40 | 130 |
| Lettuce | 3.5 | 4 | $4.00 | 80 |
| Spinach | 2.5 | 9 | $5.50 | 60 |
| Kale | 3.0 | 2 | $4.80 | 70 |
| Carrots | 4.5 | 16 | $2.00 | 90 |
| Snap beans | 2.5 | 8 | $3.30 | 100 |
| Peas | 1.5 | 9 | $5.00 | 100 |
| Potatoes | 5.5 | 1 | $1.50 | 180 |
| Onions | 4.0 | 9 | $1.80 | 80 |
| Garlic | 2.0 | 9 | $8.00 | 15 |
| Broccoli | 2.5 | 0.7 | $3.30 | 150 |
| Corn (sweet) | 1.2 | 1.5 | $1.00 | 130 |
| Sweet potato | 3.5 | 1 | $2.20 | 180 |
Yield figures represent average garden production under good growing conditions. Sources: USDA, UC Cooperative Extension, Harvest to Table.
Frequently asked questions
How accurate are the yield estimates?
The figures are population averages drawn from USDA data and university extension trials under good growing conditions. Your actual yield can be 50% lower if the soil is poor or irrigation is irregular, or 20-30% higher if you use intensive organic beds with regular feeding. Treat the output as a planning benchmark, not a guarantee, and adjust the usable-yield percentage down if you are new to gardening or if your growing season is short.
Why does the calculator recommend so many plants for small crops like radish and carrots?
Root crops and cut-and-come-again greens are planted at much higher densities than fruiting vegetables. Radishes, for instance, are spaced just 5 cm (2 in) apart, so a 50 sq ft bed can hold more than 100 plants. The high plant count reflects the spacing guidelines for intensive gardening, where you use nearly every square inch of soil rather than leaving wide open rows.
How do I calculate yield from row length instead of area?
Multiply the row length by the row width to get the total area, then enter that area in the calculator. A standard kitchen-garden row is about 30-45 cm (12-18 in) wide. For example, a single 10-foot row of beans with a 12-inch-wide bed is roughly 10 sq ft; three such rows give 30 sq ft. Enter that figure and the calculator handles the rest.
What does "successive sowing cycles" mean?
Some crops - lettuce, radishes, spinach, peas, and beans - mature quickly enough that you can clear the bed and replant it within the same growing season. Each complete plant-to-harvest sequence counts as one cycle. If you sow lettuce every six weeks and complete three full harvests before frost, enter 3. The calculator multiplies the base yield by the number of cycles to give a season total.
How do I find a good retail price to enter?
Check your nearest grocery store or farmers market for the current price per pound or per kilogram. Organic prices are typically 30-80% higher than conventional, so if you grow organically, use the organic shelf price to get the most realistic savings figure. If you leave the price field at zero the calculator falls back to a built-in national average from USDA retail data.
Why is corn yield so low per square metre?
Sweet corn produces only one or two ears per plant and needs to be planted in blocks (not single rows) for wind pollination, so the edible yield per square metre is lower than for most other vegetables. A 50 sq ft patch realistically produces about 8-12 ears. If you want a high-calorie, high-yield crop for the same space, potatoes, zucchini, or tomatoes return more food per square foot.
Can I use this for a raised bed or container garden?
Yes. Enter the interior planting area of the raised bed in square feet or square metres. For containers, estimate the total surface area of all pots dedicated to that crop. Keep in mind that containers tend to dry out faster and may need more frequent watering and feeding, which can slightly reduce yields compared to in-ground beds.