ULV Fogger Calibration Calculator
Turn a measured flow rate, ground speed and swath width into the fluid ounces per acre your fogger is really applying, check it against the label band, and size the block.
How this is calculated
A ULV machine does not apply a rate, it applies a flow. The rate is what that flow works out to once you divide it by the ground you cover while it is running, which is why speed and swath are half the arithmetic.
Ground ULV, per acre:
acres_per_min = swath_ft × speed_mph × 88 ÷ 43,560
oz_per_acre = flow_oz_per_min ÷ acres_per_min
flow to hit a label rate = rate_oz_per_acre × acres_per_min
speed to hit a label rate = flow_oz_per_min × 43,560
÷ (rate_oz_per_acre × swath_ft × 88)
Timed catch:
flow_oz_per_min = volume_collected_oz × 60 ÷ seconds
Space spray, per 1,000 cu ft:
product_oz = (volume_cu_ft ÷ 1,000) × rate_per_1000
run_minutes = product_oz ÷ flow_oz_per_minConstants. 88 feet per minute per mile per hour (5,280 ÷ 60, exact); 43,560 square feet per acre; 128 fluid ounces per gallon. Those three are definitions, not label figures, and they are the only numbers on this page that are not editable.
Worked example, the default. You catch 1.9 fl oz in 30 seconds, so your machine is putting out 3.8 fl oz a minute. At 10 mph on the 300 ft swath the Clarke ANVIL 10+10 ULV label uses for acreage, you cover 300 × 10 × 88 ÷ 43,560 = 6.06 acres a minute, so 3.8 ÷ 6.06 = 0.63 fl oz per acre. That is a shade over the label maximum of 0.62, and the tool says so: at that flow you would need 10.1 mph, or at 10 mph you would need 3.76 fl oz a minute.
Checking the arithmetic against the label itself. The Clarke ANVIL 10+10 ULV label prints its own flow-rate table for a 300 ft swath: 0.62 fl oz per acre needs 1.9, 3.8, 5.7 and 7.6 fl oz per minute at 5, 10, 15 and 20 mph. This formula reproduces that table to within a tenth of a fluid ounce at every row, and the unit tests assert it, so the engine is verified against a primary source rather than against itself.
What the verdict is, and is not. There is no invented plus-or-minus tolerance here. The band is the label's own range: Clarke ANVIL 10+10 ULV states 0.21 to 0.62 fl oz of product per acre (0.0012 to 0.0036 lb sumithrin per acre) for ground ULV, at truck speeds of 5 to 20 mph, and caps a site at 0.0036 lb of sumithrin or PBO per acre in a single application or in any 24-hour period. Over the maximum is a label violation, not a near miss. Leave the band blank and the tool returns your rate with no verdict at all rather than inventing a standard.
Sources for the presets. Clarke ANVIL 10+10 ULV (EPA Reg. No. 8329-62, label accepted by EPA on 9 May 2024) supplies the ground application band, the 300 ft acreage swath, the 5 to 20 mph vehicle speed range, the backpack arm (0.21 to 0.62 fl oz per acre on a 50 ft swath at 2 mph), the ground droplet specification of a Dv0.5 under 30 microns with Dv0.9 under 50 microns, the backpack specification of under 100 microns VMD, and the annual calibration requirement. Riptide Waterbased Pyrethrin ULV (MGK, EPA Reg. No. 1021-1785) supplies the space spray rates of 1 fl oz of concentrate per 1,000 cu ft undiluted, 1 to 2 fl oz of diluted product per 1,000 cu ft, and 1 fl oz of a 1-to-4 dilution per 1,000 cu ft in federally inspected meat and poultry plants. For a product we did not read a label for, the custom preset ships blank rather than borrowing another product's numbers.
A ULV machine does not apply a rate. It applies a flow, in fluid ounces a minute, and the rate per acre is something that happens afterwards, decided by how fast you drove and how wide the cloud carried. That is why two crews running the same product out of the same model of fogger can be a factor of four apart on label compliance and both think they are fine.
The measurement is yours, the arithmetic is ours
Nothing on this page guesses what your machine puts out. There is no table of typical fogger outputs, because a typical fogger output is not a thing: the number belongs to one machine, on one day, at one nozzle and one pressure setting. You measure it, with a graduated cylinder and a stopwatch, running at operating speed with the lines primed, averaged over two or three runs. Then the tool does the part that is genuinely fiddly on the tailgate:
acres per minute = swath (ft) × speed (mph) × 88 ÷ 43,560
fl oz per acre = flow (fl oz/min) ÷ acres per minuteThe 88 is not a fudge factor, it is 5,280 feet divided by 60 minutes, so one mile per hour is exactly 88 feet a minute. The 43,560 is square feet in an acre. Those two and the 128 fluid ounces in a gallon are the only numbers on this page that are not editable, because they are definitions rather than label figures.
Checked against a label, not against itself
The Clarke ANVIL 10+10 ULV label prints its own flow-rate table, and that is the best possible test of this engine. On its 300 foot swath, to apply 0.62 fluid ounces per acre the label calls for 1.9, 3.8, 5.7 and 7.6 fluid ounces per minute at 5, 10, 15 and 20 mph. Run those through the formula above and you get 1.88, 3.76, 5.64 and 7.52, every one within a tenth of a fluid ounce of the printed figure, with the residual being the label’s own rounding. The unit tests assert that table row by row, so the arithmetic on this page is verified against a primary source rather than against our own expectations.
The verdict is the label band, not a tolerance we invented
Some calibration pages hand you a plus-or-minus five percent pass mark. That convention is real for boom and backpack carrier calibration, where an extension service publishes it, but it does not transfer to ULV adulticiding, and we are not going to pretend it does. What ULV labels give instead is a range of allowed rates, and that range is the check. Clarke ANVIL 10+10 ULV permits 0.21 to 0.62 fluid ounces of product per acre for ground application, at vehicle speeds of 5 to 20 mph, and caps a site at 0.0036 pounds of sumithrin or PBO per acre in a single application or in any 24-hour period. Under the minimum is a pass that probably underperforms. Over the maximum is a label violation, not a near miss, and the tool words it that way.
Leave the band blank and you still get your real rate, with no verdict attached. That is deliberate: a tool that invents a standard when it does not have one is worse than a tool that stays quiet.
Two coupled effects that move the number after you measure it
Flow drifts, and it drifts for boring reasons. Formulation viscosity changes with temperature, so a rate measured on a cool morning is not the rate you get at the back end of a warm evening run. Pumps and nozzles wear. Pressure settings creep. And any deliberate change, a new nozzle, a different pressure, a different formulation, invalidates the measurement outright rather than nudging it. The Clarke ANVIL label requires annual testing of nozzle pressure and nozzle flow rate; treat that as the floor and a nozzle swap as the trigger to re-measure the same day.
Speed is half the rate. On a fixed-flow machine the fogger keeps putting out the same ounces per minute whatever the truck does, so slowing for a corner or a speed bump pushes the rate per acre up in exactly the stretch where the cloud is also densest. If your machine has speed-compensating flow control it will vary output to hold the rate, which solves that problem and creates another: a flow measured while parked tells you nothing about what the machine delivers at road speed. Either way, measure at the speed you will drive, and hold the speed you measured at.
One thing this page will never tell you is your droplet size. Flow rate and droplet spectrum are set by different mechanisms, and no volume of liquid in a cylinder implies a volume median diameter. The Clarke ANVIL label puts the requirement plainly: ground equipment must produce a Dv0.5 of less than 30 microns with 90 percent of the spray in droplets smaller than 50 microns, and that has to be set using the equipment manufacturer’s directions, the registrant’s, or a laser-based instrument at a test facility.
The indoor arm
Space spraying inside a structure is a different unit and a different formula. There is no speed and no swath: the label rate is fluid ounces per 1,000 cubic feet, so the volume of the room is the whole geometry, and your measured flow only tells you how long the machine has to run. The Riptide Waterbased Pyrethrin ULV label gives one fluid ounce of concentrate per 1,000 cubic feet undiluted, 1 to 2 fluid ounces of diluted product per 1,000 cubic feet when cut 1 part into 1 to 10 parts water, and one fluid ounce of a 1-to-4 dilution per 1,000 cubic feet in federally inspected meat and poultry plants. Switch the tool to the space arm and it works in those units instead.
What sits either side of this page
ULV is the adult, airborne half of a mosquito programme and it is not the same arithmetic as the rest of it. For barrier spray gallons and concentrate on a residential yard, that is the mosquito yard coverage calculator. For the carrier-volume calibration of the backpack or the hand-can, where the plus-or-minus five percent convention genuinely does apply, use the backpack sprayer calibration calculator. For the larval side of the same account, which is where the durable control actually comes from, that is the mosquito larvicide dosage calculator, and the wider map of rates, mixes and conversions is the pesticide dosing hub. Every pass has to end up on a record: the pesticide application log worksheet carries product, rate, area and date.
Nothing is saved, there is no account, and the exports are ungated. Treat every figure here as a planning aid. The EPA-registered label for the product in your tank is a legal document, and it is the binding rate, the binding droplet specification and the binding set of conditions for your site and your state.
Frequently asked questions
How do I calibrate a ULV fogger?
What flow rate should a truck-mounted ULV be set to?
Why does my applied rate change when I change speed?
Does the flow rate tell me my droplet size?
Why does the tool ask for a swath width I did not measure?
How often does a ULV machine need re-calibrating?
Sources
- Clarke ANVIL 10+10 ULV, EPA Reg. No. 8329-62, sumithrin 10% plus piperonyl butoxide, label accepted by EPA on 9 May 2024 (current PPLS copy). Ground application table "using a swath width of 300 feet for acreage calculations", 0.21 / 0.42 / 0.62 fl oz per acre (0.0012 / 0.0024 / 0.0036 lb sumithrin per acre) with flow rates of 0.6 to 7.6 fl oz per minute at 5, 10, 15 and 20 mph; truck mounted thermal fogging at vehicle speeds of 5 to 20 mph; backpack use at 0.21 to 0.62 fl oz per acre with a 50 ft (15.2 m) swath while walking at an average speed of 2 mph; ground droplet spec "the volume median diameter (VMD) is less than 30 microns (Dv 0.5 < 30 um) and that 90% of the spray is contained in droplets smaller than 50 microns (Dv 0.9 < 50 um)", backpack "less than 100 microns VMD"; "Application equipment must be tested at least annually to confirm that pressure at the nozzle and nozzle flow rate(s) are properly calibrated"; "Do not treat a site with more than 0.0036 lbs of Sumithrin or [piperonyl butoxide] [PBO] per acre in a single application or in any 24-hour period"; "Apply when ground wind speeds are equal to or greater than 1 mph"; "All types of applications should be conducted when temperatures at ground level are at or above 50 F". This 2024 label drops the lower droplet bounds carried by older distributor copies, which stated 8 to 30 microns for ground and 50 to 100 microns for backpack.. US EPA, Pesticide Product Label System. Retrieved .
- Riptide Waterbased Pyrethrin ULV (MGK), EPA Reg. No. 1021-1785, 5.0% pyrethrins. Product label: indoor use undiluted at one (1) fl oz of concentrate per 1,000 cu ft of space; indoor use diluted 1 part concentrate into 1 to 10 parts water at 1 to 2 fl oz of diluted product per 1,000 cu ft; federally inspected meat and poultry plants, one part concentrate to 4 parts water at one fl oz of diluted product per 1,000 cu ft of room space; dilution table for ULV foggers giving fl oz of concentrate per ounce of solution volume.. MGK, product label. Retrieved .