Fertigation EC & to PPM and Back
Converts dS/m
“Got a result worth sharing? Someone is stuck exactly where you were.
Convert EC (dS/m) to ppm with the nutrient factor (≈700), or go from ppm back to EC, and see the strength band. Read your meter the way your recipe is written.
Convert EC ↔ ppm
Next: EC sits at 1.5 dS/m — in the healthy feed range for most crops. Hold this strength.
ppm depends on the meter scale: 500 (NaCl), 640, or 700 (KCl). Always confirm which factor your meter uses before comparing readings.
EC and ppm — key facts
- EC to ppm
- ppm = EC × factor
- ppm to EC
- EC = ppm ÷ factor
- Nutrient factor
- ≈ 700 (0.7 scale)
- Other scales
- 500, 640
- EC measures
- total dissolved salts
- Reference temp
- corrected to 25 °C
- Manage by
- EC; ppm is a label
- Privacy
- Runs in your browser; nothing uploaded
Talk EC and ppm without losing the plot
Nutrient strength gets quoted two ways: EC, which a meter reads directly, and ppm, which recipes and labels often use. They are linked by a single factor — about 700 on the nutrient scale — so ppm = EC × factor and EC = ppm ÷ factor. The trap is the scale: a meter already chose one when it printed 'ppm', so match the factor here to your meter or you'll be out by up to 40%. EC is the honest number; ppm is a convenient label.
This tool gives the converted value, the EC, the ppm and a nutrient-strength band from whichever you enter. Use it to read your meter in EC and follow a recipe written in ppm, set a controller's target, and sanity-check the strength for the crop and stage. Pair it with the Fertigation Injection Time, Sulphur Nutrient and Spreader Uniformity tools for a full fertigation plan.
Convert both ways
EC to ppm or ppm back to EC in one place.
Match your scale
Pick the factor your meter uses (500, 640 or 700).
Check the strength
See the band so the solution suits the crop stage.
Set the controller
Turn a ppm recipe into the EC target a controller reads.
Frequently Asked Questions
How is EC converted to ppm?+
By a simple factor: ppm = EC in dS/m × the conversion factor, and EC = ppm ÷ the factor to go back. For nutrient solutions the factor is commonly about 700 (the so-called 700 or 0.7 scale). The tool does the conversion both ways and shows which way you converted plus a nutrient-strength band.
Why is the factor about 700?+
EC measures how well dissolved salts carry a current, which is only a proxy for total dissolved solids. Different ion mixes give different ppm per unit of EC, so the industry settled on empirical factors — roughly 700 (the 0.7 or '500/700' family) for typical nutrient solutions. It is an approximation, not a law of physics, which is why scales differ.
Which conversion scale should I use?+
There are three common scales: 500 (NaCl / Hanna), 640 (Eutech) and 700 (nutrient / Truncheon). Nutrient growers usually use 700. The catch is that a meter reading 'ppm' has already picked a scale, so match the factor here to your meter's scale — otherwise you will be off by up to 40%.
What is a typical nutrient-solution strength?+
It depends on crop and stage, but many vegetable and fruit solutions run roughly EC 1.5–2.5 dS/m (about 1,000–1,750 ppm on the 700 scale), with seedlings lower and mature fruiting crops higher. The tool flags a general band, but always follow your crop's recipe — strength that suits a tomato can scorch a seedling.
Should I dose by EC or by ppm?+
EC is the more honest measurement because it reads directly and doesn't depend on a chosen scale, so many growers manage solutions by EC. ppm is handy when a recipe or fertiliser label is written that way. This tool lets you read the meter in EC and talk to the recipe in ppm without mixing up the scale.
Does EC tell me which nutrients are present?+
No — EC is a total measure of dissolved salts and cannot distinguish nitrate from potassium from a build-up of unwanted sodium. Two solutions with the same EC can feed very differently. Use EC and ppm to manage overall strength, and a lab analysis or recipe to manage the balance of individual nutrients.
Does temperature affect the reading?+
Yes — conductivity rises with temperature, so EC meters usually report a value corrected to 25 °C. If your meter lacks automatic temperature compensation, readings drift with the solution's temperature. Measure near 25 °C or use a compensating meter so the EC you convert is the standardised value.
Can I convert ppm back to EC?+
Yes. Enter a ppm value and the tool divides by the conversion factor to give EC in dS/m, the reverse of the EC-to-ppm direction. This is useful when a recipe is written in ppm but your meter and controller work in EC, so you can set the target the controller understands.
Are the figures precise?+
The arithmetic is exact, but the EC-to-ppm link is inherently approximate because it depends on the ion mix and the chosen scale. Treat ppm as a convenient label and manage critical decisions by EC. Calibrate your meter regularly, match the scale, and confirm the strength suits the crop and stage.
Related farming tools
1900+ free tools, zero sign-up
Calculators, developer & SEO utilities, data, content, hardware and farming — all instant, private and in your browser.
Work Hours Calculator
Add up weekly work hours from a Mon-Sun punch-card timesheet. Enter clock in/out per day, subtract breaks, aut
Open FarmingIrrigation Pump VFD Energy Savings Calculator
Free irrigation pump VFD savings calculator. Enter your pump rating, duty cycle, static head and energy price
Open Dev & SEOCan You Legally Ship This Dependency Tree?
Paste package.json, package-lock.json, yarn.lock, requirements.txt, composer.lock, Gemfile.lock or Cargo.lock
Open NicheData Center Carbon Footprint Calculator 2026
Compute hyperscale, colocation and enterprise data centre annual tCO2e from IT load, PUE and grid emission fac
Open ContentImage to HDR Converter
Convert images to HDR, the high dynamic range format used for lighting, rendering and 3D scenes.
Open HardwareCPU GPU Compare Pro
Compare any two CPUs or GPUs side by side: metric-by-metric table with the winner highlighted, the performance
Open ProductivityPassword Strength Tester
Open ProAll 112 Techniques (Dharanas)
Browse the meditation techniques (dharanas) of the Vigyan Bhairav Tantra by method — breath, sound, void, ligh
Open CalculatorWork Schedule Builder
Build your weekly work schedule on a Mon–Sun × 24-hour grid. Click cells to block shifts, see total hours, get
Open FarmingIrrigation Scheduling Calculator
Free irrigation scheduling calculator. From soil texture, root depth, allowable depletion and crop ET, get the
Open Dev & SEOWhat Does This npm Package Really Install?
Type any npm package or paste your package.json and resolve the full transitive dependency tree live from the
Open NicheFleet Emissions Calculator
Quantify your fleet's annual tCO2e by vehicle type with an animated convoy and per-vehicle emission trails. Se
Open ContentImage to HEIC Converter
Convert HEIC photos to and from the modern HEIC/HEIF format used by iPhone, fast, free, bulk.
Open HardwareHardware Benchmark Database Pro
Searchable, sortable CPU and GPU database: normalized performance index, perf-per-dollar and perf-per-watt, ti
Open ProductivityPassword Tools
Test password strength against real standards (NIST 800-63B, OWASP ASVS), check against known breaches via k-a
Open ProFind a Meditation Technique by Mood & Time
Tell us how you feel and how long you have — get matched Vigyan Bhairav Tantra techniques for anxiety, restles
Open CalculatorWork Time Calculator
Add up a single day's worked time from multiple clock-in and clock-out sessions, minus breaks. Get total hours
Open FarmingIrrigation Set Volume Calculator
Free irrigation set volume calculator. Enter the system flow in litres per second, the run time in hours and t
Open Dev & SEORegex Tester & Builder
Free online regex tester with real-time match highlighting, capture-group inspection, replace/substitution, a
Open NicheOffice Energy & Carbon Calculator
Compute office annual kWh and tCO2e by climate zone, square footage, HVAC system and occupancy with a live flo
Open ContentImage to HEIF Converter
Convert images to HEIF, the modern high efficiency format that stores photos at about half the size of JPEG wi
Open HardwareHardware Specifications Explorer
Faceted CPU & GPU specification explorer: filter by type, brand, process node, release year and TDP, then read
Open ProGuided Practice
A distraction-free guided meditation session for any Vigyan Bhairav Tantra dharana — breath-paced timer, optio
Open CalculatorWorkdays From Today
Add N business days to today, skipping weekends and US federal holidays. Visible skip animation on each Sat/Su
Open