Fertilizer Blend Calculator

Custom blend proportions for target N-P-K analysis.

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Field size (acres)

Target N (lbs/acre)

Target P₂O₅ (lbs/acre)

How to Use This Calculator

Enter Field Size (acres), Target N (lbs/acre), Target P₂O₅ (lbs/acre), and Target K₂O (lbs/acre) from your soil test recommendation.
Enter the nutrient analysis (N%, P₂O₅%, K₂O%) for up to three fertilizer sources (e.g., urea 46-0-0, DAP 18-46-0, potash 0-0-60).
Review Source A, B, and C (lbs/acre) — these are the rates to apply of each product.
Check Total Product (lbs/acre) and Total Field Quantities (lbs) for each source to size purchases.
Verify the blend meets your targets by comparing Actual Delivered Nutrients to your soil test recommendations.

How the result changes with Target N (lbs/acre)

Target N (lbs/acre)	Source A (lbs/acre)	Source B (lbs/acre)	Source C (lbs/acre)
50	57.7	130.4	133.3
175	329.4	130.4	133.3
325	655.5	130.4	133.3
450	927.2	130.4	133.3

What each input means

Field size (acres): Total field area to fertilize.
Target N (lbs/acre): Desired nitrogen application rate per acre.
Target P₂O₅ (lbs/acre): Desired phosphate application rate per acre.
Target K₂O (lbs/acre): Desired potash application rate per acre.
Source A: N%: Nitrogen analysis of Source A (e.g., urea = 46%).
Source A: P₂O₅%: Phosphate analysis of Source A.
Source A: K₂O%: Potash analysis of Source A.
Source B: N%: Nitrogen analysis of Source B (e.g., DAP = 18%).
Source B: P₂O₅%: Phosphate analysis of Source B (e.g., DAP = 46%).
Source B: K₂O%: Potash analysis of Source B.
Source C: K₂O%: Potash analysis of Source C (e.g., potash/KCl = 60%).

What each result means

Source A (lbs/acre): Pounds of Source A per acre.
Source B (lbs/acre): Pounds of Source B per acre.
Source C (lbs/acre): Pounds of Source C per acre.
Total product (lbs/acre): Combined product weight per acre.
Blend % Source A: Source A fraction of the blend by weight.
Blend % Source B: Source B fraction of the blend by weight.
Blend % Source C: Source C fraction of the blend by weight.
Total Source A (lbs): Total Source A for the whole field.
Total Source B (lbs): Total Source B for the whole field.
Total Source C (lbs): Total Source C for the whole field.
Total all sources (lbs): Grand total product for the whole field.
Delivered N (lbs/acre): Actual nitrogen delivered per acre.
Delivered P₂O₅ (lbs/acre): Actual phosphate delivered per acre.
Delivered K₂O (lbs/acre): Actual potash delivered per acre.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Field size (acres) = 10, Target N (lbs/acre) = 120, Target P₂O₅ (lbs/acre) = 60, Target K₂O (lbs/acre) = 80 = 11 input(s) provided
Calculate Source A
209.8 = 209.8
Calculate Source B
130.4 = 130.4
Calculate Source C
133.3 = 133.3
Calculate Total product
Total product = sourceALbsPerAcre + sourceBLbsPerAcre + sourceCLbsPerAcre
473.6 = 473.6
Calculate Blend % Source A
44.3 = 44.3%

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