Try the interactive spreadsheet below to see how it works!

Download the full Calculator for free!

This calculator is broken into three parts:

  • ProductionCalculate the yield potential of your ZipGrow Towers
  • Revenue – Project revenue for your ZipGrow Tower operation
  • SeedlingsPlan seedling production for your farm


Keep reading for a breakdown on how to use your calculator! 

Section 1: Production Quantities Generator


(Towers per square foot)

The productivity of a given space is related to the grow space to floor space ratio, determined by your equipment and layout.


Of course, environmental conditions and the type of structure also impact spacing. This is the reason for the disparity between “greenhouse” and “indoor” numbers in Part 1 of the the Production Estimates Calculator.

In greenhouses, the light source originates from one direction. This means that all towers need to face the same way, and that spacing needs to allow light to penetrate into the plant canopy.

Most greenhouses can space ZipGrow Towers at 1 Tower per 2.5 square feet, although taller towers will require looser spacing (7-footers require 3.2 sq. ft. apiece) to ensure light penetration to the back crops.

We recommend 5-foot towers for most greenhouse operations.

In this calculation, 30% of the total square feet is reserved for maintenance aisles and movement. This does not include space for starting seeds and work benches.

In indoor farms, on the other hand, lights may be configured independently. The most efficient arrangement is inward-facing aisles, with each row back to back.

Low-heat lights allow Towers to be fairly close to lights, increasing density even more.

With 3 ZipRacks per row and 20 ZipGrow Towers per rack, most indoor spaces can count on 60 Towers in 130 sq ft.


With number of ZipGrow Towers decided, you can move on to the production estimates. As you can see, greens production is much higher than herb production. Greens are typically sold by the pound (or for heading crops like lettuce, by the “unit”), while herbs are typically sold by the ounce, or occasionally by the bunch/clamshell package.

In this example, we’re using 2000 ft² of greenhouse space (560 towers total).


Some greens are “multi-harvest” crops. This means that growers only harvest 30% of the plant during the first harvest period, and continue to harvest 30% each consecutive month. The number of harvests a grower gets out of a green depends on the type of crop and the health of the crop. This type of harvesting can result in higher production numbers per plant.


Pin down the variables. Plant production is highly variable depending on the environment and health of the crops. Understanding the amount of useful light (PPFD), light ratios (blue:red), nutrient balance, pest management, and other factors allows growers to hone in on production details. Eventually, growers will develop a personalized production estimates plan.


Production estimates are key to generating revenue estimates. Plug in expected production numbers to planting schedules and forecast your ability to meet client needs in your markets.

Section 2: Revenue Estimates Generator


Pricing is calculated by multiplying pounds per tower (production) by the percentage of Towers that grow that crop. Pounds of production is then multiplied by pricing. Remember: only change the pricing and percentages; leave the white cells as they are.

Retail pricing is marked up 50%. (In other words, the retail price is 150% of wholesale.)


Growers should conduct market research of their own, since each local market is slightly different. Different groups of consumers demand different crops and amounts of crops, and each community is made up of different markets.

Surveying and face time with your prospective markets will do wonders for getting accurate pricing estimates. Enter this customized information into Part 2 of the Production Estimates Calculator.


The revenue estimates listed in the Production Estimates Calculator are a great starting point to discovering your farm’s potential revenue based on pricing in your area. To round this out with ongoing and upfront expenses, energy expenditures, etc., start a conversation with one of our farm startup experts.

*Expenses are not factored into the Revenue Estimator.

Section 3: Seedling Generator


The seed planting numbers listed in Part 3 of the Production Estimates Guide are conservative, factoring in a 10% loss of seedlings between planting and harvest and assuming the most dense seedling spacing in ZipGrow Towers.

Gather information and tips on growing great quality seedlings:

Balancing light & electricity costs


Information on assumptions

Almost every indoor farmer shares a goal when it comes to crop yield: identify and remove bottlenecks. In other words, find what’s keeping your crops from growing to their full potential – and change it!

Bottlenecks occur in three main areas that define plant health: light, nutrient solution, and environment. The data included in the Production Estimates Calculator were drawn from a “healthy” system – a system using good practices in each of these areas. Read on to explore the guidelines that define a healthy system.

Give your plants the amount and type of light they need.

It’s easy to underestimate how much light a plant requires to grow. In fact, over half of the problems that indoor growers have with plant growth are due to lack of light. To understand how much light to deliver to plants, you have to understand DLI.

DLI is measured in mol·m-2·d-1. Notice that DLI is measured in similar units as PAR, only in the context of one day. For example, 12-14 mol·m-2·d-1 is the recommended DLI for lettuce production in greenhouses and even higher DLI values (15-20+) are required for fruiting crops.

To learn more about delivering light, read the Modern Farmer’s Guide to Artificial Lighting.

If you’re going to strive for lighting greatness, you must be aware of the costs and other needs associated with intensive lighting. Heat output is a huge influence of lighting on the surrounding environment. Growers must be prepared to deal with heat output with airflow, farm layout, and of course by choosing low-heat lighting. HVAC and other heat removal costs will be a significant cost on your farm, so choose heat removal equipment that will function well and last a long time. (Serious indoor growers will consider water-cooled lights, which reduce the amount of heat that escapes into the growing environment.)

Nutrient solution

The nutrient solution that you use on the your farm determines whether the plant are receiving most of the inputs they need to survive. Your system should move the solution with enough pressure and turbulence to provide adequate flow rates and oxygenation (for plant roots).

Flow rates: Establish good flow rates by sizing a pump to your system. (Choosing a slightly larger pump than necessary is wise and can save you money if you scale up in the future.) ZipFarm users can have their pump sized by the Bright Agrotech installation team.

Oxygen: Oxygenation is key to avoiding anaerobic zones, which damage plant roots. In systems like DWC, air stones are necessary to oxygenate water. In ZipGrow Tower system, turbulence in the sump tank and mixing tank should oxygenate the water sufficiently.

Flow rates: Establish good flow rates by sizing a pump to your system. (Choosing a slightly larger pump than necessary is wise and can save you money if you scale up in the future.) ZipFarm users can have their pump sized by the Bright Agrotech installation team.

Oxygen: Oxygenation is key to avoiding anaerobic zones, which damage plant roots. In systems like DWC, air stones are necessary to oxygenate water. In ZipGrow Tower system, turbulence in the sump tank and mixing tank should oxygenate the water sufficiently.


Oxygen is just one of 16 plant nutrients. Hydrogen, oxygen, and carbon are provided to plants through its environment (water and air), but other nutrients are delivered to plants through the nutrient solution.

The key measurement for nutrient levels is EC, or electrical conductivity. Keeping the number of nutrients (in a hydroponic system, present as salts) in the right range is key. Growers can find a good target range by choosing crops with overlapping range values in the Recommended Crop List.

Choosing a fertilizer that is formulated for your type of crops (greens, fruiting, etc.) is key to providing nutrients in the right ratios. Different crops take up nutrients at slightly different rates from each other. If the wrong formula is used for a crop, then crops will grow deficient in certain nutrients faster and more severely.

Though deficiencies should be rare if growers are using the correct formula, they may still occur. Growers can use a resource like the Nutrient Deficiency Identification Key to identify and treat deficiencies.

Hydroponic systems should be flushed every 3-6 months, unless nutrient imbalance is occurring aggressively (in which case, growers should consider switching to a different fertilizer formula). This “resets” the nutrient ratios in the system to help avoid deficiencies in the long term. To flush a system, turn off all pumps and empty the system. Running a sanitizing solution through the system before rinsing and refilling it can help with disease control. This can also be a great time to clean gutters and tanks of any salt build up or algae, etc. When the system is clean (and well-rinsed!), refill it and balance your solution’s pH and EC.


Environmental quality is important not only to creating good growing conditions, but to reducing pests and diseases. The key factors of environmental quality are temperature, moisture, airflow, and cleanliness.

Temperature (finding an overlapping value). Temperature should be maintained within a range that fits all crops. Methods for heating and cooling a growing space include HVAC and fans, heaters and boilers, cooling walls, shade cloth, etc. For indoor growers, heating and cooling can be largely controlled by good lighting equipment and HVAC systems. (Learn more about heating and tips on cooling.)

Other nutrient bottlenecks: CO2. Carbon is a macronutrient of plants (needed in relatively high quantities, and is closely related to crop yield. Plants can only acquire carbon one way: through CO2. CO2 should be supplemented especially in indoor environments. Learn more about how to supplement CO2 here.

Pests & disease: Discouraging the entry and spread of pests in your system is key to consistent growth and yields (and therefore revenue!). Pest and disease enter the system very easily and can spread rapidly as well, so exclusion and sanitation are extremely important.

Exclusion – Complete exclusion of pests can be very difficult, but growers can reduce the amount of pests and disease entering their environment by keeping an exclusion room near entry areas. This is a room that reduces the direct airflow and tracking of debris into the growing space. It’s wise to use different shoes and brush off clothes before entering growing spaces as well.

Cleanliness and sanitation – like exclusion, there are many best practices that growers can implement to drastically reduce the chance of disease and insect pests. Sanitizing equipment between uses (like harvesting knives, rags, and buckets) with a mild bleach solution and keeping areas free of debris like fallen plant leaves is key here. This keeps diseases and insects from surviving to re-infest later on.

Management for a Healthy System

Though many problems can be planned for and avoided by good management, dealing with issues that do arise requires historical data. If you don’t know when your crops have been vulnerable to a pest problem, or when different workers were working in the system, etc. then it is much harder to deal with problems. The absolute best thing you can do to save time dealing with problems is to keep good records! Designing your maintenance schedule to limit the number of interactions and keep tasks simple will also help.


Calculate how much you can grow in the ZipFarm, with data for specific crops.

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