# Fertilizer N-P-K Blend Calculator Compute how to mix base fertilizers to hit a target N-P-K analysis like 10-10-10. Outputs per-fertilizer kg plus a parts ratio for any batch size. > Canonical page: https://elysiatools.com/en/tools/fertilizer-blend-calculator - **Category:** Utilities - **Keywords:** fertilizer, npk, blend, calculator, urea, dap, potash, mixing ratio, gardening, agriculture, 10-10-10 ## Overview Find the right mix of base fertilizers to hit a target N-P-K analysis (e.g. **10-10-10**), and get the per-fertilizer amount for any batch size. **How it works** 1. Enter your **target analysis** — the three numbers on a fertilizer bag, e.g. `10-10-10` or `5-10-15`. 2. List the **base fertilizers** you have on hand, one per line: `Name = N-P-K`. Example: `Urea = 46-0-0`, `DAP = 18-46-0`, `Potash = 0-0-60`. 3. Set the **total batch weight** (kg) you want to mix. 4. The tool solves the blend mass balance — how much of each base fertilizer plus inert filler/carrier to combine so the final batch's N-P-K analysis matches your target as closely as possible. **What you get** - **Blend recipe**: exact kg of each base fertilizer, any **filler/carrier kg** needed to reach the final batch weight, plus a **parts ratio** for the active fertilizers. - **Achieved N-P-K**: what the final batch actually delivers, and a **match score** (0–100% — 100% means the target analysis is matched). - **Diagnostic notes**: if the exact target is unreachable with your bases, the tool tells you the closest achievable analysis and why. **Convention**: N-P-K uses the %N — %P₂O₅ — %K₂O form (what's printed on every bag). A target of 10-10-10 means a 100 kg batch should contain 10 kg N, 10 kg P₂O₅, and 10 kg K₂O; inert filler is added when the nutrient sources do not fill the whole batch. **Built-in reference**: 12 common commercial fertilizers (urea, DAP, MAP, TSP, muriate of potash, SOP, etc.) are available to copy into the input — but you can declare any custom analysis. ## Inputs - **Target N-P-K (e.g. 10-10-10)** (text): The three numbers on a fertilizer bag: %N - %P₂O₅ - %K₂O. - **Available fertilizers (one per line: Name = N-P-K)** (textarea): The base fertilizers you can mix. One per line: Name = N-P-K. Copy from the reference table below or declare your own. - **Total batch weight (kg)** (number): How many kg of final blend you want to produce. The recipe scales to this. ## When to use - When you need to mix custom fertilizer ratios for specific crop growth stages using raw bulk ingredients like urea, DAP, and potash. - When you want to scale a fertilizer recipe to a specific total batch weight in kilograms while maintaining precise nutrient percentages. - When you need to determine if a target N-P-K ratio is mathematically achievable with your current inventory of base fertilizers. ## How it works - Enter your target N-P-K analysis representing the desired percentages of nitrogen, phosphate, and potash. - List your available base fertilizers and their respective N-P-K values, with each entry formatted on a new line as Name = N-P-K. - Specify the total target batch weight in kilograms to scale the final recipe. - The calculator solves the mass balance equations to output the exact weight of each base fertilizer, the required inert filler, and the achieved N-P-K match score. ## Use cases - Creating balanced all-purpose garden fertilizers from single-nutrient bulk ingredients. - Formulating high-phosphorus bloom boosters for specific flowering phases using MAP and sulfate of potash. - Adjusting agricultural fertilizer applications to match soil test recommendations using available farm inventory. ## Frequently asked questions ### What does N-P-K stand for in this calculator? It represents the percentage by weight of Nitrogen (N), Phosphate (P₂O₅), and Potash (K₂O) in the fertilizer. ### Why does the recipe include an inert filler? Filler is added to reach the target batch weight when the active nutrient sources do not fill the entire batch volume. ### What happens if my target N-P-K ratio is unreachable? The tool will calculate the closest possible match, display the achieved N-P-K values, and provide diagnostic notes. ### Can I use custom base fertilizers not listed in the reference? Yes, you can input any custom fertilizer by writing its name and N-P-K values in the text area. ### What unit of measurement does the calculator use? The calculator uses kilograms (kg) for the batch weight and individual fertilizer amounts. ## Related tools - [Interior Paint Coverage Estimator](https://elysiatools.com/en/tools/interior-paint-coverage-estimator): Estimate how many buckets of interior paint you need from room dimensions, doors/windows, coats, paint coverage, and bucket size — rounded up to whole buckets, with optional primer and waste factor. - [Nepali Bikram Sambat & Thai Solar Calendar Bridge](https://elysiatools.com/en/tools/nepali-bikram-sambat-and-thai-solar-calendar-bridge): Convert any date between Gregorian (AD), the Nepali Bikram Sambat (BS) calendar, and the Thai solar (Buddhist Era, BE) calendar. Shows the BS month-length table for the year and explains the algorithm. - [Day of Year Converter](https://elysiatools.com/en/tools/day-of-year-converter): Convert any date to its day-of-year number (1-366) and back, with ISO week number, leap-year check, and days remaining in the year. - [ISO Week Number and Fiscal Quarter Anchor Finder](https://elysiatools.com/en/tools/iso-week-number-and-fiscal-quarter-anchor): Convert any date to ISO 8601 week number, day-of-year, Julian Day, and fiscal-quarter boundaries (4-4-5, 4-5-4, 13-week, or standard). - [AI Domain Name Idea Generator](https://elysiatools.com/en/tools/ai-domain-name-idea-generator): Generate up to 10 creative domain names with AI and filter out already-registered ones via DNS + RDAP. - [APNG IDAT/fdAT Chunk, Streaming Deflate Replay and Disposal Method Frame-Timing Analyzer](https://elysiatools.com/en/tools/apng-idat-fdat-chunk-streaming-deflate-replay-and-disposal-method-analyzer): Upload a PNG or APNG and audit the whole animation structure: PNG signature and per-chunk CRC32 checks, IHDR bit depth / color type / interlace, acTL placement and declared frame counts, every fcTL (region bounds inside the canvas, normalized delay fractions, dispose_op none/background/previous, blend_op source/over), the shared fcTL+fdAT sequence-number contract from 0, per-frame replay of the IDAT/fdAT deflate streams with exact decompressed-size verification, and disposal-semantics audit — first-frame PREVIOUS treated as BACKGROUND, zero-delay frames, loop counts, fps and compression ratios. - [Buoyancy Calculator (Archimedes, F = ρ·V·g)](https://elysiatools.com/en/tools/buoyancy-calculator): Compute buoyant force, fluid density, or displaced volume from any two, with optional float/sink analysis - [Cohort Retention & RFM Funnel Analyzer](https://elysiatools.com/en/tools/cohort-retention-rfm-funnel-analyzer): Paste an order or event CSV and get the growth stack in one page: a cohort retention triangle with a heatmap, RFM quintile scoring mapped to the ten standard lifecycle segments, and a strict-order funnel. ## Samples - [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion - [Android Image Processing Java Samples](https://elysiatools.com/en/samples/android-image-processing-java): Android Java image processing examples including reading/saving images, scaling, and format conversion - [Android Image Processing Kotlin Samples](https://elysiatools.com/en/samples/android-image-processing-kotlin): Android Kotlin image processing examples including reading/saving images, scaling, and format conversion - [Web Image Processing Rust Samples](https://elysiatools.com/en/samples/web-image-processing-rust): Web Rust image processing examples including image read/save, scaling, and format conversion