Microgreen Seed Calculator
Estimate seed per tray, total seed weight, germinated stand, soak time, harvest timing, expected fresh yield, crop loss, and weekly tray production for microgreens.
Use your own test harvest records when available. Microgreen yield changes with seed lot, blackout time, airflow, light, watering, cut height, and harvest stage.
Microgreen Seed Plan
Results combine tray area, selected density mode, germination, crop loss, soak time, and harvest cycle.
| Crop | Typical seed per 10x20 | Germination planning | Soak time | Harvest window |
|---|---|---|---|---|
| Broccoli | 0.9 to 1.2 oz | 88% to 95% | 0 hours | 9 to 12 days |
| Radish | 1.3 to 1.8 oz | 85% to 95% | 0 hours | 7 to 10 days |
| Sunflower | 4 to 5 oz | 80% to 92% | 8 to 12 hours | 9 to 12 days |
| Pea shoots | 7 to 10 oz | 85% to 95% | 8 to 12 hours | 10 to 14 days |
| Cilantro | 1.2 to 2 oz | 65% to 85% | 8 to 16 hours | 14 to 21 days |
| Tray size | Area | Scale vs 10x20 | Broccoli seed | Sunflower seed |
|---|---|---|---|---|
| 5x5 sample tray | 25 sq in | 0.125x | 0.13 oz | 0.56 oz |
| 10x10 half tray | 100 sq in | 0.50x | 0.50 oz | 2.25 oz |
| 10x20 full tray | 200 sq in | 1.00x | 1.00 oz | 4.50 oz |
| 12x24 shelf tray | 288 sq in | 1.44x | 1.44 oz | 6.48 oz |
| Custom tray | Length x width | Area / 200 | Rate x scale | Rate x scale |
| Adjustment | Calculator use | Typical range | What it affects |
|---|---|---|---|
| Germination | Multiplies live stand and yield estimate | 65% to 98% | Usable crop density and expected harvest |
| Crop loss | Subtracts unsold, culled, or failed crop share | 3% to 20% | Sellable or usable fresh yield |
| Yield ratio | Fresh weight divided by dry seed weight | 1.5x to 9x | Harvest estimate by tray and batch |
| Soak time | Adds to active cycle timing | 0 to 16 hours | Schedule overlap and batch planning |
| Tray area | Scales density when using g per sq in | 25 to 288 sq in | Seed per tray and total seed |
| Trays per week | 10 day crop active trays | 14 day crop active trays | Approx sow interval | Planning note |
|---|---|---|---|---|
| 5 trays/week | 8 trays | 10 trays | 1.4 days | Small stand or trial production |
| 10 trays/week | 15 trays | 20 trays | 0.7 days | Regular restaurant or market supply |
| 25 trays/week | 36 trays | 50 trays | 0.3 days | Needs dedicated rack space and wash flow |
| 50 trays/week | 72 trays | 100 trays | 0.1 days | Batch by crop so soaking and harvest stay controlled |
| 100 trays/week | 143 trays | 200 trays | 0.1 days | Use written crop schedules and lot tracking |
Before scaling: Run one test tray per crop and seed lot. Record dry seed weight, harvest weight, days, and cull percentage, then replace preset values with your own numbers.
Before ordering seed: Convert weekly trays into weekly seed weight, then add a small inventory buffer for late deliveries, retests, and crop failures.
Seed Rates
The rate of the seeds that should be planted is one of the most critical factor in the growth of microgreens. The rate of the seeds will determine the density of the microgreens that are grown in the tray. Using too little seed will leave parts of the tray bare.
Using too much seed will result in the competition of the roots for the nutrients of the soil, the air, and the growing space for the plants. Furthermore, the excess seed will interfere with the airflow within the tray and will result in the waste of money that was spent on purchasing the seeds. It is, therefore, necessary to calculate the rate of the seeds that will result in an evenly growth of the microgreens.
What You Need for the Microgreens Calculator
Tray Dimensions
The dimensions of the trays in which the seeds will be planted are another essential input for the calculator. The dimensions of the tray will determine the total amount of growing area for the microgreens. Using small trays will produce less of the crop than if you used large trays.
The number of seeds that is planted must be adjusted according to the size of the tray. Germination Percentage of Seed
The germination percentage of the seeds is another essential input. The germination percentage will indicate how many of the planted seeds will germinate into the plants that will produce the microgreens.
Using a seed with a high germination percentage will require fewer seeds to be planted than a seed with a low germination percentage. The percentage of seeds that will not germinate must be accounted for when planting the seeds to ensure that enough microgreens are produced. Seed Soak Time and Days to Harvest
The soak time of the seeds and the number of days it takes for the microgreens to be harvested are two additional inputs for the calculator.
Large seeds, such as sunflower and pea seeds, will require the seeds to be soaked overnight in water to allow the seeds to absorb the water and begin to germinate. The soak time will add to the total number of days that the seeds are grown before they are harvested. The total number of days that the seeds are grown will determine how many trays the microgreens will occupy within the growing area.
Yield Ratio and Crop Loss Percentages
The yield ratio and the percentage of the crop that is lost are two additional inputs for the calculator. The yield ratio will determine the number of ounces of fresh microgreens that can be harvested from each ounce of dry seed. The percentage of the crop that is lost will determine how much of the harvested crop cannot be sold.
This percentage is due to the fact that not all microgreens will have even growth. The percentage will be subtracted from the total gross harvest to determine the weight of the net harvest of the fresh microgreens. Reference Tables
The reference tables within the calculator will provide information on the yield ratio and the percentage of the crop loss for common crops.
Additionally, the reference tables will provide the dimensions for the trays for both sample and production areas. These reference tables can be used to replace the preset numbers within the calculator with your own data regarding your own germination and harvest weights. Using your own data for these variables will allow the calculator to reflect the specific conditions of your greenhouse.
Using the Calculator
The calculator can be used to make adjustments to the variables if the results of the calculation dont match those of your own microgreen plots. The yield ratio may need to be adjusted if the basil microgreens that you are growing are lighter than those calculated by the ratio. Additionally, if the radish microgreen plants are growing faster than calculated, you can shorten the number of days for the crops to be harvested.
Using fewer days for the harvest cycles will allow more trays of crops to be grown in the greenhouse each month. These variables can be adjusted to reflect the results of your plots within the greenhouse. Planning Seed Inventory
Another reason to use the calculator is to create a plan for the inventory of the seeds that will be used to grow the microgreens.
By calculating the number of trays of microgreens that will need to be planted each week and the amount of seed that will be used for each tray, you can calculate the total amount of seed that will be needed. Additionally, some extra seed should of be purchased for these calculations to ensure that there is an extra batch of seeds in case of test runs or failed batches of seeds within the greenhouse. Arithmetic of the Calculator
The main function of the calculator is to allow the individual grower to perform the mathematics that would otherwise be performed on paper or on a spreadsheet.
The calculator does not make any decisions for the grower. However, the grower must make decisions about which numbers will be used for the variables in the calculator. When the variables match the actual growing of the microgreens, the schedule for harvesting the crops will become a plan that the grower can follow each cycle.
