Injector Ratio Calculator for Gardening

Calculator Inputs

Enter the injector setting, stock tank size, irrigation run, and desired outlet dose. The results appear above this form after submission.

Injector ratio denominator

For a 1:100 injector, enter 100.

Stock tank size (L)

Planned irrigation volume (L)

Desired final dose (mL/L)

This is the fertilizer amount at the outlet.

Product density (g/mL)

Product price per liter ($)

Example Data Table

Ratio	Stock Tank (L)	Irrigation (L)	Final Dose (mL/L)	Density (g/mL)	Price/L	Stock Strength (mL/L)	Product for Tank (mL)	Water to Add (L)	Treatable Water (L)	Stock Used (L)	Product Used (mL)	Mass (g)	Cost
1:100	20.00	800.00	2.00	1.12	$18.50	200.00	4,000.00	16.00	2,000.00	8.00	1,600.00	1,792.00	$29.60

Formula Used

Let:

R = injector ratio denominator for 1:R
D = desired final fertilizer dose in mL/L
B = stock tank size in L
V = planned irrigation water volume in L
ρ = product density in g/mL

Main equations:

Stock strength (mL/L stock) = D × R
Product for full tank (mL) = D × R × B
Water to add in stock tank (L) = B − (Product for full tank ÷ 1000)
Treatable water from one full tank (L) = B × R
Stock used for planned irrigation (L) = V ÷ R
Product used for planned irrigation (mL) = D × V
Product mass (g) = Product used × ρ
Run cost = (Product used ÷ 1000) × price per liter

These relationships work well for liquid fertilizer injection planning in gardens, greenhouse lines, raised beds, containers, and drip systems.

How to Use This Calculator

Enter the injector ratio denominator. Use 100 for a 1:100 injector.
Enter the stock tank size in liters.
Enter the total irrigation water volume planned for the run.
Enter the desired final fertilizer dose in mL per liter.
Enter product density to estimate mass more accurately.
Enter product price per liter if you want cost estimates.
Press the calculate button.
Review the results above the form, then export them as CSV or PDF.

Frequently Asked Questions

1. What does a 1:100 injector ratio mean?

It means one part stock solution is drawn for every one hundred parts of irrigation water. The outlet concentration depends on both that ratio and the stock solution strength.

2. What should I enter for desired final dose?

Enter the fertilizer amount you want plants to receive at the outlet, measured in mL of product per liter of final irrigation water.

3. Why can the water to add become negative?

A negative value means your target outlet dose is too strong for the chosen injector ratio and stock tank volume. You need a larger tank, a lower dose, or a different injector setting.

4. Why does the calculator show stock used for the run?

That value tells you how much concentrate the injector will pull during your planned irrigation event. It helps you confirm whether one stock tank is enough.

5. Does density matter for every calculation?

Density mainly affects estimated product mass. The dilution math uses volume, while density helps convert that volume into grams for inventory or nutrient planning.

6. Can this be used for greenhouse and drip irrigation?

Yes. It is suitable for drip lines, greenhouse benches, raised beds, container zones, and other setups using a liquid fertilizer injector.

7. Can I use gallons instead of liters?

You can, but convert everything to liters first for correct results. Keeping all inputs in one unit system prevents dilution mistakes.

8. Should this replace label directions?

No. Always check the product label, crop needs, and water quality. This tool helps with mixing math, not crop-specific feeding prescriptions.