Key takeaways
- Size means different things by job: for spray and spread drones it is tank and payload; for mapping drones it is sensor type and flight endurance. Match the spec to the work, not to the biggest number.
- Spray coverage scales with payload: a mid-size spray drone covers roughly 10 to 15 hectares an hour, while a heavy-lift unit reaches 25 to 30 hectares an hour, cutting refills and time in the paddock.
- Mapping drones are about endurance and sensors: a compact mapping drone can survey around 200 hectares on a single battery, with the sensor (RGB, multispectral, thermal) deciding what data you get.
- Bigger payload means more ground support: heavy spray drones need more charging infrastructure and often a two-person rig, so capacity has a setup cost beyond the drone.
- Weight sets your licence too: the heavier the drone, the more involved the CASA credential, so size affects both coverage and paperwork.
Introduction
"What size agricultural drone do I need?" is the wrong question until you split it by job. Spraying, spreading and mapping each measure size differently, and buying for the wrong axis is how operations end up with a machine that cannot keep pace, or one far larger than the work requires. This guide breaks size down by the three main agricultural drone families so you can self-select the right capacity for your operation and your hectares.
Sizing a spray or spread drone: tank and payload
For spray and spread drones, the headline spec is payload, the weight of liquid or granular product the drone carries per load. Payload drives coverage, and coverage drives how much ground you clear before the work window closes. The two practical brackets in the Australian market sit roughly as follows.
Mid-size spray drones (around 40-litre tank)
A mid-size spray drone carries around 40 litres and covers roughly 10 to 15 hectares an hour. It suits smaller properties, mixed operations, hilly or irregular paddocks, and growers trialling drone spraying for the first time. Two mid-size drones flown in tandem are a common way to lift coverage without stepping up to a heavy unit. This class is manageable for a single operator and needs less ground support.
Heavy-lift spray and spread drones (up to around 75-kilogram payload)
Heavy-lift drones carry up to around 75 kilograms of product and cover 25 to 30 hectares an hour with a single unit, with the largest setups clearing 200 hectares or more in a day. They suit broadacre cropping and larger contract work where ground covered per day is the priority. The trade-off is infrastructure: faster, bigger batteries need serious charging support, and the rig is best run by two people or a well-organised solo operator. For spreading granular product such as seed, fertiliser or baits, the same payload logic applies, expressed in kilograms rather than litres.
Matching payload to your spray window
The practical test is whether the drone can cover your area inside the hours conditions allow. Spraying is limited to suitable wind and daylight, so your effective window is narrow. Take your paddock area, divide by the drone's hourly coverage, and check the result fits the window you realistically get. If a mid-size drone covers it, you avoid the extra setup of a heavy unit. If it does not, the heavy-lift class, or a second drone, earns its place. It helps to compare agricultural drones by tank and payload side by side before deciding.
Sizing a mapping or survey drone: sensors and endurance
Mapping and survey drones flip the logic. These are lightweight aircraft, and "size" is about how long they stay airborne and what sensor they carry, not how much they lift. A compact mapping drone can survey around 200 hectares on a single battery, which covers most properties in a flight or two.
Choosing the sensor
The sensor decides what you learn. A standard RGB camera captures visual imagery for general mapping and inspection. A multispectral sensor reads light beyond the visible range to produce crop-health indices such as NDVI (a measure of plant vigour) and NDRE (a measure tuned to detect nutrient stress in dense canopy), which flag stressed zones before they are visible on foot. A thermal sensor reads surface temperature to find irrigation problems and is also used in livestock work. An RTK module (real-time kinematic positioning) adds centimetre-level location accuracy for precise, repeatable maps.
Matching the mapping drone to your operation
For routine crop scouting, a compact multispectral drone with good endurance covers the job at modest cost. Larger or more complex properties benefit from RTK precision and longer flight time to reduce the number of flights. The key is that you are buying data capability and airtime, not lifting capacity.
Sizing a livestock monitoring drone
Drones used to check herds, water points and fencing are built around camera reach rather than payload. A strong optical zoom lets you count and assess animals from a distance, and a thermal sensor helps locate stock in poor light or cover. On large or remote properties, autonomous "drone-in-a-box" systems run scheduled flights for routine checks without a pilot travelling the property. Here, size is really about camera capability, range and flight time, matched to how far your stock and infrastructure are spread.
Common questions from agricultural drone buyers
How many hectares can an agricultural spray drone cover per hour?
A mid-size spray drone covers roughly 10 to 15 hectares an hour, and a heavy-lift unit around 25 to 30 hectares an hour. Actual coverage varies with application rate, wind and temperature, so treat these as planning figures rather than guarantees.
Is a bigger drone always better?
No. A larger payload means more charging infrastructure and often a two-person rig, so the right size is the smallest drone that covers your area inside your working window. Oversizing adds setup cost you may not need.
What size drone do I need just for crop mapping?
Mapping is about sensors and flight time, not payload. A compact multispectral drone that surveys around 200 hectares per battery covers most properties, with RTK precision worth adding for repeatable, accurate maps.
Can one drone both spray and map?
Some operations run a heavy drone for spraying and a separate lightweight drone for mapping, because the two jobs need different airframes. A few platforms support swappable functions, but most buyers match each drone to its primary task.
Does drone size affect my licence?
Yes. Heavier drones require a Remote Pilot Licence rather than basic accreditation, so stepping up in size also steps up the credential you need. Factor the licensing pathway into your sizing decision.
What matters most
Size your agricultural drone by the job: payload and coverage for spray and spread work, sensor and endurance for mapping, camera reach for livestock. The smallest drone that clears your area inside your working window is usually the right buy, because capacity beyond that adds infrastructure and licensing weight. When you are ready, get quotes for agricultural drones across these classes and compare on the spec that matches your work. For the wider buying picture, see our agricultural drone buying guide, and licensing detail in the sections above.
Find the right agricultural drone
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