Paint Calculator for Airless Sprayer
Estimate coating quantity, prime volume, tip flow, pump margin, spray time, and adjusted paint for airless sprayer projects.
Choose a starting point, then adjust the surface area, coating coverage, tip, transfer efficiency, hose, and waste values for your job.
Airless Sprayer Paint Estimate
| Tip size | Fan width | Orifice | Approx flow | Best fit | Surface note |
|---|---|---|---|---|---|
| 310 | 6 in | 0.010 in | 0.11 gpm | Fine enamel | Cabinets, rails, trim |
| 412 | 8 in | 0.012 in | 0.16 gpm | Doors and trim | Smooth panels |
| 515 | 10 in | 0.015 in | 0.24 gpm | Interior latex | Walls and ceilings |
| 517 | 10 in | 0.017 in | 0.31 gpm | Exterior acrylic | Siding and fences |
| 519 | 10 in | 0.019 in | 0.39 gpm | Heavy latex | Rough siding |
| 521 | 10 in | 0.021 in | 0.47 gpm | Masonry coat | Block and stucco |
| 523 | 10 in | 0.023 in | 0.57 gpm | Elastomeric | Roof or high build |
| 625 | 12 in | 0.025 in | 0.67 gpm | High build | Large open areas |
| Coating or project | Typical coverage | Solids range | Transfer range | Common loss driver |
|---|---|---|---|---|
| Interior wall latex | 325 to 400 sq ft/gal | 34 to 42% | 75 to 85% | Masking edges and cut-ins |
| New drywall primer | 250 to 325 sq ft/gal | 28 to 36% | 78 to 88% | Porous paper and joint compound |
| Exterior acrylic siding | 250 to 350 sq ft/gal | 35 to 45% | 60 to 75% | Lap edges and wind drift |
| Deck or fence stain | 150 to 250 sq ft/gal | 20 to 35% | 45 to 65% | Open boards and rough grain |
| Fine finish enamel | 300 to 450 sq ft/gal | 32 to 48% | 70 to 85% | Test sprays and strain waste |
| Block filler or masonry coat | 75 to 150 sq ft/gal | 45 to 60% | 50 to 68% | Deep texture and pinholes |
| Elastomeric roof coating | 50 to 125 sq ft/gal | 50 to 65% | 55 to 75% | High film build and surface profile |
| Hose setup | Internal diameter | 25 ft volume | 50 ft volume | 100 ft volume |
|---|---|---|---|---|
| Whip or small line | 3/16 in | 0.04 gal | 0.08 gal | 0.15 gal |
| Common paint hose | 1/4 in | 0.08 gal | 0.16 gal | 0.31 gal |
| Long run latex hose | 3/8 in | 0.18 gal | 0.36 gal | 0.72 gal |
| High-output supply hose | 1/2 in | 0.32 gal | 0.64 gal | 1.27 gal |
| Preset | Area | Coverage | Tip | Transfer | Waste |
|---|---|---|---|---|---|
| Interior Drywall Walls | 1200 sq ft | 350 sq ft/gal | 515 | 78% | 8% |
| Flat Ceiling Repaint | 650 sq ft | 325 sq ft/gal | 515 | 76% | 9% |
| Exterior Lap Siding | 1800 sq ft | 290 sq ft/gal | 517 | 64% | 12% |
| Rough Wood Fence | 900 sq ft | 190 sq ft/gal | 517 | 52% | 14% |
| Deck Stain Spraying | 520 sq ft | 210 sq ft/gal | 412 | 58% | 12% |
| Cabinet Enamel Doors | 240 sq ft | 390 sq ft/gal | 310 | 82% | 10% |
| Metal Railing Enamel | 320 sq ft | 360 sq ft/gal | 412 | 68% | 12% |
| Split Face Block | 700 sq ft | 115 sq ft/gal | 521 | 55% | 16% |
| New Drywall Primer | 1500 sq ft | 290 sq ft/gal | 515 | 84% | 7% |
| Elastomeric Roof Coat | 1100 sq ft | 85 sq ft/gal | 523 | 62% | 15% |
Airless spraying change the amount of paint that is required to complete a job because the paint does not travel direct from the paint can to the area to be painted. Some of the paint that comes out of the airless sprayer may drift past the painted surface, it may soak into the grain of the material that is to be painted, and it may remain within the sprayer’s hose if the spray gun are paused during the job or if colors is changed. It is essential that the airless sprayer operator have an accurate estimate of the amount of paint that will be required for the job.
If the estimate are not accurate, it is possible that the individual may run out of paint part way through applying a second coat of paint. It is for these reasons that it is recommended that you use a dedicated paint calculator for airless sprayer job. The paint calculator will ask for several different input to determine the amount of paint that will be required for a project.
How Much Paint You Need for Airless Spraying
Beyond the area to be painted and the number of coats that will be applied to that area, there are several other factors that contributes to the amount of paint that will be required. One of these factors is the coverage that is claimed of the paint manufacturer’s label. Another factor is the percentage of the paint that will remain after the water evaporate.
Another of these factors is the transfer efficiency of the paint; the amount of paint that land on the painted area. As the wind increase or if spraying operations are performed on open railings or on areas with rough surface, the transfer efficiency of the paint will decrease. The paint calculator will account for the paint that is lost due to low transfer efficiency.
Additionally, the paint calculator will account for the overspray that will need to be masked or wipe away from the painted areas. The paint calculator will also determine the amount of paint necessary to prime the hose to ensure that the paint that exits the tip of the airless sprayer is the same color as the paint that was used to fill the sprayer. Another of the factors that the paint calculator will consider is the size of the tip of the airless sprayer.
The size of the tip will determine the amount of coating that can come out of the airless sprayer in one minute. A 515 tip will allow more paint to emerge from the airless sprayer then a 310 tip; however, the pump that powers the airless sprayer will have to deliver enough pressure to the paint to ensure that the fan of paint emerges in a clean pattern from the tip regardless of the size of the tip. If the pressure from the airless sprayer pump is too close to the amount of paint that emerges from the tip, the pressure will drop as the airless sprayer move along the area to be painted.
This drop in paint pressure can lead to a poor finish on the painted area. Thus, the paint calculator will flag this issue prior to beginning to spray paint onto the wall. In addition to determining how much paint will be required to complete the job, the paint calculator will also calculate the length of time that will be required for the spraying job.
The paint calculator will calculate the amount of time that the airless sprayer’s trigger will need to be activated to perform the painting job; this time will be referred to as the active trigger time. Additionally, the paint calculator will calculate the length of time that will be required for the field work to complete the job; this time will be referred to as the field time. The field time will likely be more longer than the active trigger time because the field time includes any breaks that may be taken during the painting job.
The coverage rates for paint as described on the paint can are established under the assumption that the surfaces to be painted is smooth and under ideal conditions. In the real world, the paint coverage rates may not be met on rough or even uneven painted areas. For instance, a new application of drywall primer will likely sink into the compound that fills the joints of the drywall panels.
Exterior siding may be exposed to the wind. The end grain of a fence may take the stain from the paint that emerges from the airless sprayer. An adjustment of the paint’s coverage and waste allowance fields in the paint calculator will allow for the amount of paint required to account for the way in which the paint will behave on the painted areas.
The percentage of the paint that will remain once the water evaporates will allow the paint calculator to determine the amount of dry film paint will provide; this value will allow the painter to determine if two coats will provide the correct thickness of paint. Another factor that must be considered is the amount of paint that will remain in the hose. A fifty foot section of quarter inch hose will contain more than a pint of paint.
This paint will have to be accounted for prior to the paint reaching the area to be painted. The paint calculator will account for the amount of paint that will remain in the hose once the length of the hose and the diameter of the hose are enter into the paint calculator. For jobs that require the airless sprayer to move long distances or to use large diameter hoses, the amount of paint that will remain in the hose becomes a very important factor in the cost of the painting job.
The volume of paint will have to be accounted for when using expensive type of finish coat paint. Another of the factors that the paint calculator will ask of the painter using the paint calculator is the allowance for waste of paint. This waste can occur due to the paint that remains on the strainers that are used in the airless sprayer, the amount of paint that is used for test sprays, and the amount of paint that may be used in making touch up passes on areas of the project that were painted too light or too dark.
The percentage of the waste of paint can be increased in the paint calculator to provide for an extra amount of paint that will allow the painter to avoid run out of paint during the job. The type of surface that will be painted can also be selected in the paint calculator; this selection will automatically adjust the amount of paint that is recommended for the project. By using the paint calculator prior to ordering the paint that will be used in the painting project, the painter will avoid any error.
Errors that may be created by using paint calculators that are not specifically designed for airless sprayers may include the painter assuming that the coverage rate indicated on the paint can will work on each and every type of surface. Errors may also be created by the painter forgetting about the amount of paint that will be lost due to overspray. Low transfer efficiency of the paint will require the painter to purchase more gallons of paint than if the paint had higher transfer efficiency.
The amount of paint that must be used to prime the hose will have to be purchased in addition to the amount of paint required to color the painted area. Each adjustment that is made in the paint calculator will lead to a change in the final total amount of paint that will be required for the project. The paint calculator will provide a total amount of paint that is required to complete the project.
This total amount of paint should be present at the job site prior to starting the compressor that will power the airless sprayer. The paint calculator will not replace the painter’s experience with the type of project that must be completed; however, it will eliminate the need for the painter to remember the math behind the calculations for the project.
