Free HVAC and refrigeration calculators

R410A PT Chart (410A Pressure Temperature)

Look up the R-410A saturation pressure for a temperature, or the temperature for a gauge reading, and print the full chart.

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This R410A PT chart, also searched as a 410A pressure temp chart, lists the saturation pressure of R-410A at every temperature. The R-410A PT chart calculator gives the pressure and temperature pairs for R-410A refrigerant. Enter a temperature to find its saturation pressure, or enter a pressure to find its saturation temperature, and the tool returns the matching value with a full chart table below it.

R-410A was the standard refrigerant for US residential air conditioners and heat pumps from 2010. Newer residential split systems are moving to lower-GWP refrigerants from 2025, so R-410A is now mainly used to service existing equipment. The calculator runs in your browser, is free, and needs no sign-up. Nothing you enter is uploaded. This page explains how to use it, how to read a PT chart, and what the gauge units mean.

R410a pt chart example

How to use the R-410A PT chart calculator

  1. Set Refrigerant to R-410A. To see a worked case first, click the “R-410A at 40 °F” example button.
  2. Set Convert to “Temperature → pressure” if you know the temperature, or to “Pressure → temperature” if you have a gauge reading.
  3. Fill in the input that matches your mode. The Saturation temperature field or the Gauge or absolute pressure field appears only in some modes. For a standard gauge reading, pick psig.
  4. Set Chart units: °F and psig, °C and bar (gauge), or °C and kPa (gauge). The units apply to the result and to the chart table.
  5. Read the result rows. Only the rows that apply to your mode appear. For R-410A, the liquid and vapor values are nearly the same, so you get one pressure.
  6. Open More options if needed. Set Chart table step (Auto, 1, 2, 5 or 10 degrees), and enter Altitude above sea level only if you are not at sea level.
  7. Scroll to the R-410A pressure–temperature table under the result and find your row.
  8. Open How it was calculated to see the formula and each step with your numbers.

Use Copy result to copy the result lines with a link, or Copy link to save every input so the same calculation reopens later. Print / save as PDF includes the inputs, results, steps and the date. Reset restores the starting example.

How do you read a PT chart?

A PT chart pairs each temperature with the pressure at which the refrigerant boils or condenses at that temperature. This is the saturation pressure. To read it, find your temperature in the left column and read across to the pressure. For example, R-410A at 40 °F is 118.8 psig, at 70 °F is 201.7 psig, and at 120 °F is 419.5 psig at sea level. Pressure rises quickly as temperature rises, so a few degrees can change the reading noticeably.

The chart temperature is the real refrigerant temperature only where liquid and vapor are both present, such as in the evaporator or condenser. In a superheated suction line or a subcooled liquid line the pressure is still about the evaporator or condenser pressure, but the pipe temperature is not the chart temperature: the difference between the two is the superheat or the subcooling. R-410A has very little temperature glide, so the calculator uses a single pressure column for it. When the system is off, still holds liquid refrigerant and has reached air temperature, the pressure reads the chart value for that temperature. This is the standing pressure, and it is the easiest check of a chart.

Is a PT chart in psig or psia?

A PT chart in psig gives gauge pressure, which is measured relative to the surrounding air. Most refrigeration gauges read psig. The chart values in this calculator are gauge pressures at sea level. Absolute pressure, in psia, is measured from a perfect vacuum. At sea level, psia = psig + 14.696. So 201.7 psig at 70 °F equals about 216.4 psia.

Air pressure drops with altitude, so a gauge reads differently at higher elevations. The Altitude above sea level field in More options accounts for this. If you need absolute values for calculations, use psia or the kPaa and bara options.

Sources

Data and methods used by this calculator (checked October 2026):

Worked examples

InputResult
R-410A, 40 °F118.8 psig
R-410A, 120 °F419.5 psig
R-410A, 118 psig39.65 °F
R-410A, 5 °C8.349 barg

Calculated by the tool above with these values.

Frequently asked questions

What is the pressure of R-410A at 70 °F (standing pressure)?

At sea level, R-410A at 70 °F is 201.7 psig, which is about 216.4 psia. This is the reading you see on a gauge when the system is off and has reached 70 °F.

What should R-410A pressures be when running?

There is no single running pressure. It depends on the evaporator and condenser temperatures. The chart gives the saturation pressure for those temperatures, such as 118.8 psig at 40 °F or 419.5 psig at 120 °F. For target values, use the equipment manufacturer’s charts and charging instructions.

Why is the suction line warmer than the PT chart temperature?

The chart temperature is the real refrigerant temperature only where liquid and vapor are both present, such as in the evaporator or condenser. The suction pressure is close to the evaporator pressure, so the chart gives the evaporator’s saturation temperature, but the vapor in the suction line has picked up superheat after the last liquid boiled off. That difference is the superheat; the superheat calculator works it out for you.

Can I use gauges and hoses rated for R-22 with R-410A?

No, not safely. R-410A runs at roughly 60 % higher pressure than R-22, so gauges, hoses and recovery equipment must be rated for R-410A.

What is the critical temperature of R-410A?

R-410A’s critical temperature is about 160 °F (71.3 °C). Above this temperature, the refrigerant cannot exist as a liquid, whatever the pressure. R-410A is ASHRAE safety class A1.

Can I use the results in quotes or service records?

Yes. Results, charts and printouts can be used freely in commercial work such as quotes, proposals, reports and service records, with no attribution needed. For critical designs, verify the values against the applicable standard.