Calculate ammonia levels from mass, volume, or percent. Convert units, estimate NH3 fraction by pH. Export results to files and validate with examples quickly.
Choose an input method. Large screens show three columns, then two, then one.
| Scenario | Inputs | Output (mg/L as NH3) |
|---|---|---|
| Mass + volume | 0.25 g in 1.0 L | 250.0000 |
| Direct concentration | 2.0 mg/L as NH3-N | 2.4280 |
| % w/w + density | 0.10% w/w, 1.00 g/mL, 500 mL | 1000.0000 |
Total ammonia can be expressed as molecular ammonia (NH3) or as nitrogen (NH3-N). Environmental permits, aquaculture limits, and wastewater compliance commonly specify NH3-N, while dosing and reaction work may use NH3. This tool converts between forms using molecular weights: 17.031 g/mol for NH3 and 14.007 g/mol for nitrogen, so mg/L as N equals mg/L as NH3 multiplied by 14.007/17.031.
In dilute water-like samples, ppm is approximately equal to mg/L, so 3 mg/L is about 3 ppm. For concentrated or nonaqueous matrices, percent w/w plus density provides a more defensible concentration because volume is no longer “water-like.” Example: 0.10% w/w at 1.00 g/mL contains 1.0 g NH3 per liter of solution, which is 1000 mg/L. If density is 1.05 g/mL, the same percent becomes 1050 mg/L.
Molarity supports reaction stoichiometry, breakpoint chlorination planning, and dosing control. The calculator converts mg/L to mol/L by dividing by 1000 to obtain g/L, then dividing by 17.031. For instance, 50 mg/L equals 0.050 g/L and corresponds to 0.00294 mol/L. When calculating reagent demand, molar units reduce rounding error and align directly with balanced equations and kinetic models.
Only a fraction of total ammonia is present as unionized NH3, and that fraction rises with higher pH and higher temperature. The tool estimates pKa with pKa = 0.09018 + 2729.92/T(K), then applies fraction NH3 = 1/(1+10^(pKa−pH)). At 25°C and pH 9, the unionized fraction is many times higher than at pH 7, which matters for odor, volatilization, and aquatic toxicity screening.
Accuracy depends on representative sampling, clean containers, and prompt analysis because ammonia can volatilize or be biologically transformed. Use duplicates and blanks when decisions are high-stakes. Validate entries by cross-checking mass and volume: 0.25 g in 1 L must equal 250 mg/L. If results look unrealistic, confirm units, decimal placement, and temperature units, and record the final values with the calculator’s CSV or PDF export for traceability. For field work, note that handheld meters may drift; periodic calibration and temperature compensation reduce bias, especially when measuring low mg/L ranges outdoors quickly.
It reports ammonia on a nitrogen basis. Convert to mg/L as NH3 by multiplying by 17.031/14.007. Convert back by multiplying mg/L as NH3 by 14.007/17.031.
For dilute water-like solutions, ppm is effectively mg/L. In dense or concentrated solutions, ppm can deviate; use percent w/w with density to compute a more realistic mg/L value.
They estimate the unionized NH3 fraction using an equilibrium relationship. Higher pH and temperature increase unionized NH3, which is often the more critical form for odor and toxicity screening.
The tool treats results as total ammonia expressed as NH3-equivalent and can estimate the NH3/NH4+ split. If you start from ammonium salt mass, convert to equivalent ammonia based on stoichiometry first.
Enter a concentration and also provide a volume. The tool multiplies mg/L by liters to estimate total mass in milligrams, which you can convert to grams by dividing by 1000.
Confirm units, rerun with a known example (0.25 g in 1 L = 250 mg/L), and compare NH3 vs NH3-N outputs. Large jumps usually indicate a misplaced decimal or mismatched units.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.