EC to PPM Converter Tool
Accurate nutrient measurements are essential for healthy hydroponic growth. Our EC to PPM Converter makes it easy to translate electrical conductivity (EC) readings into all common PPM scales, including 500, 650, and 700. Whether you’re adjusting nutrients, troubleshooting feed charts, or switching brands, this free tool gives you precise, reliable conversions so you can grow confidently.
Universal EC to PPM Converter
Precision conversion for all major hydroponic meter scales.
Why are there three scales?
Digital meters don’t actually “count” the number of particles in your water; they measure electrical flow (EC). To show you a PPM (Parts Per Million) number, the meter has to multiply that EC by a “conversion factor.”
- The 500 Scale (0.50 factor) is the US standard.
- The 700 Scale (0.70 factor) is the international standard (UK/EU/Australia).
- The 650 Scale (0.65 factor) is a specialized scale used primarily by Milwaukee and Nutridip meters to provide a “middle ground” accuracy for specific mineral salts.
Using the wrong scale can cause you to over-fertilize or under-fertilize your plants by up to 30%.
Once you’ve checked your readings, explore our other hydroponic tools to optimize growth:
- Nutrient Mixing Calculator – Calculate exactly how much nutrient solution to add based on your reservoir size.
- Hydroponic Light Distance Calculator – Determine safe and effective hanging heights for all types of grow lights.
- Hydroponic System Selector Tool – Find the ideal system size and type for your space.
- Reservoir Top Off Calculator – Use this after mixing your nutrients to maintain the perfect balance. It calculates the exact amount of fresh water needed to fix EC spikes as your plants drink throughout the week.