MistGuideCalculators

Misting system calculators

Run the numbers before you buy anything. These tools use the same planning figures as our guides, show their formulas, and work on any phone without sign-ups.

  • Misting cooling potential calculator

    Estimate how much a misting system can cool your air from temperature and humidity: wet-bulb limit, likely misted temperature and heat index before and after.

  • Nozzle and pump sizing calculator

    Work out how many misting nozzles a line needs, their total flow at your pressure, and the smallest pump class that runs them with safe headroom.

  • Misting water use and running cost calculator

    Calculate how many gallons a misting system uses per hour, day and season, plus water and pump electricity cost, from nozzle count and runtime.

  • Nozzle flow at pressure calculator

    Convert a misting nozzle's rated flow to any operating pressure using the square root rule, with a full flow table from 100 to 1,500 psi.

  • Greenhouse VPD calculator

    Calculate greenhouse vapor pressure deficit from temperature, humidity and leaf temperature offset, with target ranges for propagation, growth and flowering.

Which calculator to start with

Most misting projects go wrong in one of three places: the climate is too humid for the system chosen, the pump cannot hold pressure across the nozzle count, or running costs surprise the owner in August. The calculators follow that order.

  1. Will misting work where you live? Start with the cooling potential calculator. It finds the wet-bulb limit for your afternoon conditions and shows how much the feels-like temperature will actually change.
  2. What hardware do you need? The nozzle and pump sizing calculator turns line length, spacing and orifice size into a nozzle count and a pump class.
  3. What will it cost to run? The water use and cost calculator gives gallons per season and the combined water and electricity bill.
  4. Working from a spec sheet? The flow at pressure converter puts nozzle ratings at different pressures on the same footing.
  5. Growing plants? The VPD calculator tells you whether your greenhouse air is pulling too much or too little water from leaves.

How these tools are built

Every calculator runs entirely in your browser; nothing you type is sent anywhere. The physics are standard and published: the Stull wet-bulb formula, the National Weather Service heat index equation, the Tetens vapor pressure equation, and the orifice flow relationship. Where a tool needs a judgment call, such as how effective open-air misting is compared with a swamp cooler, the page labels it as a planning assumption and explains where it comes from. Our research methodology describes how those figures are chosen and reviewed.