In a drone's power system,motor size is one of the most critical yet easily overlooked parameters.It not only determines the physical dimensions of the motor but also profoundly influences thrust,efficiency,KV matching,propeller selection,and the overall flight characteristics of the aircraft.
Different motor sizes correspond to entirely different flight styles and application scenarios:
Micro-motors allow Tiny Whoops to navigate nimbly indoors.
Mid-sized motors provide the explosive power for 5-inch FPV racing drones.
Large-sized motors support long-endurance cruising and heavy-lift flight platforms.
A lack of understanding of motor size often leads to blind selection and a loss of efficiency,resulting in issues such as insufficient thrust,excessive current draw,and poor performance.Mastering the mainstream motor size ranges allows you to quickly pinpoint a suitable power configuration when designing or modifying a drone.
This article will systematically break down the fundamental concepts,performance characteristics,and common applications of mainstream drone motor sizes.It will also provide a practical size reference chart to help you quickly find the right motor among dozens of models.If you want to gain a more comprehensive understanding of drone motor selection logic,working principles,and performance parameters,you can refer to our complete Drone Motor Guide.Whether you are an FPV pilot,an aerial photography enthusiast,or an industry professional,you will gain a clearer understanding of"why size determines performance"after reading.
I.What is Drone Motor Size and What is its Function?
In a drone's power system,"Motor Size"is one of the most fundamental parameters.It defines the geometric specifications of the motor's stator and directly dictates the motor's output capability,compatible propeller size,and the aircraft's overall flight style.
1. Motor Size Naming Convention
Drone motor size is typically represented by two sets of numbers,such as 2207 or 2306.The first two digits indicate the stator diameter(in mm),and the last two digits indicate the stator height(in mm).For example,a 2207 motor has a stator that is 22 mm in diameter and 7 mm in height.
Variations in diameter and height lead to changes in torque,power handling capacity,response characteristics,and weight.This labeling method has become the universal standard in the FPV and multirotor fields.
2. Stator Diameter:Influencing Torque and Propeller Drive Force
A larger stator diameter results in a longer magnetic flux radius and a greater lever arm,leading to stronger torque output.
Small Diameter(e.g.,1103,1404):Lightweight and agile,but with limited thrust.
Medium Diameter(e.g.,2205,2306):Balances thrust and maneuverability,making it the mainstream choice for 5-inch FPV drones.
Large Diameter(e.g.,2806,3508):Suitable for large propellers,with powerful torque for long-endurance and industrial aircraft.
The stator diameter is the most critical dimension as it determines whether the motor can effectively drive large propellers.
3. Stator Height:Influencing Power and Current Handling Capacity
A taller stator provides a larger winding volume,allowing the motor to handle more current and deliver greater power output.
Low Height(e.g.,2305,2306):Quick response with moderate power.
Tall Height(e.g.,2208,2808):Capable of sustained high-power output,ideal for high-payload missions.
For the same diameter,a taller motor can provide stronger continuous thrust but also increases weight and energy consumption.
4. Size and Weight:Affecting Response and Flight Characteristics
As motor size increases,the iron core,windings,and magnets become heavier.
Small Motors:Are lightweight with low rotational inertia,allowing for rapid acceleration and deceleration,perfect for agile maneuvers.
Large Motors:Are heavier and have a slightly slower response but offer greater stability and higher thermal capacity,making them suitable for long-endurance flights.
For example,a 2306 motor weighs around 30–35 g,whereas a 2806 motor can exceed 50 g.This weight difference directly impacts the flight dynamics.
II.What Motor Sizes Should Be Used for Different Types of Drones?
Different types of drones have distinct mission objectives and flight characteristics,which in turn dictate the appropriate motor size.
From ultra-light Tiny Whoops to industrial heavy-lift platforms,there is a clear matching relationship between motor size,propeller size,KV value,and battery voltage(S-count).Understanding these mainstream ranges can help you quickly narrow down a suitable power system during design or modification.
1. Tiny Whoops/Micro Drones
Typical Motor Size:0503–0803
Propeller Size:31–40 mm(1.2–1.6 inches)
KV Range:18,000–25,000 KV
Battery:1S
Characteristics:Extremely lightweight and responsive,primarily used for indoor or micro FPV flights.These drones do not require a high thrust-to-weight ratio but prioritize sensitivity and flight time,often using high-KV,direct-drive motors.
2. Micro FPV Drones(2–2.5 inches)
Typical Motor Size:1103–1404
Propeller Size:2–2.5 inches
KV Range:8,000–12,000 KV
Battery:2S–3S
Characteristics:Lightweight and agile,suitable for beginners or flying in smaller areas.These models have a lower demand for explosive power but emphasize maneuverability and a light throttle response.
3. 3-inch Cinewhoops/Beginner FPV Drones
Typical Motor Size:1404–1507
Propeller Size:3 inches
KV Range:4,000–6,000 KV
Battery:3S–4S
Characteristics:Compact yet powerful,often used for light-payload aerial filming or entry-level FPV flying.These motors balance thrust and weight,making them ideal for Cinewhoop platforms with enclosed propeller guards.
4. 4-inch Mid-Sized FPV Drones
Typical Motor Size:1606–2004
Propeller Size:4 inches
KV Range:3,000–4,500 KV
Battery:3S–4S
Characteristics:Strikes a balance between agility and flight distance.These models can achieve high speeds while also offering moderate flight times.
5. 5-inch FPV Racing/Freestyle/Cruising Drones
Typical Motor Size:2205–2306
Propeller Size:5 inches
KV Range:1,700–2,500 KV
Battery:4S–6S
Characteristics:This is the most popular size in the FPV world,known for its powerful and agile performance.It is suitable for racing,freestyle,and general cruising,making it the core platform for FPV enthusiasts.
6. 6-inch Long-Range FPV Drones
Typical Motor Size:2306–2507
Propeller Size:6 inches
KV Range:1,300–1,900 KV
Battery:4S–6S
Characteristics:Balances thrust and efficiency,making it a popular choice for long-endurance and mid-to-long-range flights.A lower KV combined with larger propellers and moderate voltage provides excellent efficiency and extended flight times.
7. 7-inch Long-Range/Cruising Drones
Typical Motor Size:2507–2806.5
Propeller Size:7 inches
KV Range:900–1,800 KV
Battery:4S–6S
Characteristics:Primarily focused on cruising and endurance,often used for"Long Range"flights.7-inch drones are typically paired with low-to-mid KV motors to achieve a good balance of efficiency,thrust,and wind resistance.
8. 8-inch Aerial Photography Platforms
Typical Motor Size:2806.5–3008
Propeller Size:8 inches
KV Range:850–1,200 KV
Battery:6S–8S
Characteristics:Efficient,stable,and with ample thrust,suitable for aerial photography and stable flight missions.8-inch motors are larger and heavier but significantly improve wind resistance and payload capacity.
9. Aerial Photography/Light-Payload Industrial Platforms(9–10 inches)
Typical Motor Size:3008–3508
Propeller Size:9–10 inches
KV Range:700–1,000 KV
Battery:6S–8S
Characteristics:Emphasizes long flight times and stability,often used for commercial filming and inspection tasks.Compared to 8-inch setups,this size class offers greater propeller efficiency and a stronger lift reserve.
10. Industrial Drones/Heavy-Lift Platforms
Typical Motor Size:3508–5008+
Propeller Size:11–13 inches+
KV Range:300–800 KV
Battery:6S–12S
Characteristics:Suitable for logistics,agricultural spraying,inspections,and emergency response.These motors are large and powerful,typically used on multi-axis heavy-lift platforms,prioritizing efficiency,stability,and durability.
III.Drone Motor Size Chart
After understanding the basic definitions and performance logic of motor sizes,we can apply this knowledge to practical selection.
There is a very clear corresponding relationship between frame wheelbase,propeller size,motor size,and KV value.Mastering this chart will allow you to quickly identify the appropriate power range when designing or upgrading a drone,avoiding trial and error.
Below is a reference table for motor sizes,compiled based on current mainstream FPV,aerial photography,and industrial drone parameters:
Motor Size (Stator) | Frame Wheelbase (mm) | Prop Size | KV Range (Typical) | Battery (S) | Notes |
0503–0803 | 55–85 mm | 31–40 mm (1.2–1.6″) | 18,000–25,000 KV | 1S | Tiny Whoop / indoor micro |
1103–1404 | 85–120 mm | 2″–2.5″ | 8,000–12,000 KV | 2S–3S | Micro quad / toothpick |
1404–1507 | 120–140 mm | 3″ | 4,000–6,000 KV | 3S–4S | Lightweight cinewhoop |
1606–2004 | 155–180 mm | 4″ | 3,000–4,500 KV | 3S–4S | Small–medium FPV |
2205–2306 | 195–225 mm | 5″ | 1,700–2,500 KV | 4S–6S | Mainstream FPV / freestyle / racing |
2306–2507 | 250–270 mm | 6″ | 1,300–1,900 KV | 4S–6S | Long range FPV |
2507–2806.5 | 300–330 mm | 7″ | 900–1,800 KV | 4S–6S | Long range / endurance |
2806.5–3008 | 360–390 mm | 8″ | 850–1,200 KV | 6S–8S | Aerial platform |
3008–3508 | 400–500 mm | 9″–10″ | 700–1,000 KV | 6S–8S | Aerial / light industrial |
3508–5008+ | 500 mm+ | 11″–13″+ | 300–800 KV | 6S–12S | Heavy lift / industrial platform |
IV.Frequently Asked Questions(FAQ)
1. If motor sizes are the same,do different brands perform very differently?
Yes.Even if the stator dimensions are identical,differences in winding techniques,magnet quality,bearing precision,and heat dissipation design between brands can lead to performance variations.For instance,the thrust difference between two 2207 motors from different manufacturers could be as high as 15%–25%.This is why high-end motors in the same size class are generally more expensive and offer better efficiency and stability.
2. Can I mix motors of different sizes?
It is not recommended.Mixing motor sizes will cause uneven thrust,increase the workload on the flight controller for compensation,and lead to increased vibration and reduced efficiency.The only common exception is in specific differential thrust designs(like X8 coaxial setups)where top and bottom motors may differ.For a standard multirotor,all motors should be the same size.
3. Which has a greater impact on flight performance:motor size or KV value?
Both are essential,but size determines the potential upper limit,while KV defines the response characteristics.Motor size affects the maximum thrust and the compatible propeller range,whereas the KV value influences the throttle curve and efficiency.When selecting motors,you should first determine the general power class based on size,then fine-tune the flight style with the appropriate KV.
4. Is there a difference in maintenance difficulty for different motor sizes?
Yes.Small motors have intricate structures and are difficult to repair if damaged;they are often replaced entirely.Medium and large motors are easier to disassemble for bearing replacement or stator repair,but they are also more expensive.For high-payload aircraft,regular bearing maintenance and checking for shaft runout are particularly important.
5. Can motor size affect the drone's vibration and video stability?
Yes.Larger motors offer better wind resistance and have greater rotational inertia,which generally results in smoother flight footage.However,if they become unbalanced or a bearing fails,the resulting vibrations will be more severe than those from a smaller motor.Small motors produce less intense vibrations but have poor wind resistance,which can cause jitter outdoors.Therefore,for aerial photography,a combination of appropriately sized motors,high-quality balancing,and a vibration-damping structure is essential.