E-Bike Size Guide & Fit Calculator
Not sure what size electric bike you need? Enter your measurements below and we will recommend the ideal frame size, standover clearance, handlebar width, stem length, and saddle height for your body and riding style.
Your Measurements
Visual Sizing Diagram
Enter your measurements above to see personalised sizing annotations.
Brand-Specific Size Charts
Different brands use slightly different sizing. Use the table below as a quick reference, and always check the manufacturer’s official chart before purchasing.
Specialized
| Size | Rider Height | Frame (cm) |
|---|---|---|
| S | 5'1" - 5'5" | 42-46 |
| M | 5'5" - 5'9" | 47-51 |
| L | 5'9" - 6'1" | 52-56 |
| XL | 6'1" - 6'5" | 57-61 |
Trek
| Size | Rider Height | Frame (cm) |
|---|---|---|
| S | 5'2" - 5'6" | 44-47 |
| M | 5'6" - 5'10" | 48-52 |
| M/L | 5'10" - 6'0" | 53-55 |
| L | 6'0" - 6'3" | 56-58 |
| XL | 6'3" - 6'6" | 59-62 |
Cannondale
| Size | Rider Height | Frame (cm) |
|---|---|---|
| SM | 5'3" - 5'7" | 44-48 |
| MD | 5'7" - 5'11" | 49-53 |
| LG | 5'11" - 6'2" | 54-57 |
| XL | 6'2" - 6'6" | 58-62 |
Rad Power Bikes
| Size | Rider Height | Frame (cm) |
|---|---|---|
| One Size (Step-Through) | 5'1" - 6'2" | 46 (effective) |
| One Size (Step-Over) | 5'4" - 6'2" | 51 (effective) |
| RadRover / RadRhino | 5'2" - 6'4" | 48 (effective) |
Aventon
| Size | Rider Height | Frame (cm) |
|---|---|---|
| Small (S/M) | 5'1" - 5'7" | 44-48 |
| Regular (M/L) | 5'5" - 6'2" | 49-55 |
| Large (L/XL) | 5'11" - 6'4" | 56-60 |
Giant
| Size | Rider Height | Frame (cm) |
|---|---|---|
| S | 5'3" - 5'7" | 43-47 |
| M | 5'7" - 5'11" | 48-52 |
| L | 5'11" - 6'3" | 53-57 |
| XL | 6'3" - 6'6" | 58-62 |
E-Bike Specific Sizing Considerations
Weight & Handling
E-bikes are significantly heavier than traditional bikes, typically weighing 40-70 lbs (18-32 kg) due to the motor, battery, and reinforced frame. This extra weight affects balance and handling, especially at low speeds and when mounting or dismounting. If you are between sizes, consider sizing down for better control and confidence, particularly if you are new to cycling.
Step-Through vs Step-Over Frames
Step-through (low-entry) frames make mounting and dismounting much easier, which is especially important given the extra weight of an e-bike. They are an excellent choice for riders with limited flexibility, those carrying cargo, or anyone who frequently stops in urban traffic. Step-over frames offer slightly more structural rigidity and are often preferred for aggressive mountain or road riding.
Battery Placement & Center of Gravity
Battery placement significantly affects how an e-bike handles. Mid-frame (downtube) batteries provide the lowest and most centred center of gravity, offering the most natural ride feel. Rear-rack batteries shift weight backward, which can feel less balanced. Integrated batteries are sleeker and often better balanced. When sizing, consider that a lower center of gravity generally makes a slightly larger frame more manageable.
Standover Height Matters More
Because e-bikes are heavier, having adequate standover clearance is even more critical than with regular bikes. Aim for at least 2-5 cm (1-2 inches) of clearance between the top tube and your inseam when standing flat-footed. This gives you a safety margin when you need to stop suddenly.
Motor Type & Sizing Interaction
Hub motors (front or rear) add weight to the wheel, which can affect steering feel on smaller frames. Mid-drive motors centralise weight near the bottom bracket, which tends to feel more natural across all frame sizes. If you are choosing a hub-motor e-bike and are between sizes, test ride both to see which feels more stable.
How to Test Ride an E-Bike
A size calculator gives you a great starting point, but nothing replaces an actual test ride. When you visit a shop, pay attention to standover clearance, reach to the handlebars, saddle comfort, and how confident you feel controlling the bike at low speed. E-bikes accelerate faster than you expect, so make sure you are comfortable with the brakes and handling before committing.
- Wear the shoes you will normally ride in
- Stand over the frame with both feet flat — check clearance
- Sit on the saddle and check that your leg is nearly fully extended at the bottom of the pedal stroke
- Ride at low speed in a car park to test balance with the extra weight
- Test all assist levels and make sure brakes feel confident
- Try starting from a stop on a slight incline
Find Your Perfect Fit
Our top picks by rider size. Links may earn us a commission at no extra cost to you.
Related Resources
How to Test Ride an E-Bike: 12-Point Checklist
Make the most of your test ride with our comprehensive checklist.
E-Bike Weight Limits: Best Bikes for Heavy Riders (2025)
Find e-bikes with higher weight capacities and reinforced frames.
E-Bikes for Seniors: Complete Guide to Staying Active After 60
Step-through frames, comfortable geometry, and easy-to-use controls.
E-Bike Directory
Browse our complete database of e-bikes by make and model.
Frequently Asked Questions
What size e-bike do I need?
The right e-bike size depends primarily on your height and inseam length. Use the calculator above to get a personalised recommendation. As a general rule: riders 5’0”-5’4” typically fit a Small, 5’4”-5’8” a Medium, 5’8”-6’0” a Large, and 6’0”+ an XL.
Should I size up or down for an e-bike?
If you are between sizes, it is usually better to size down for an e-bike. The extra weight of the motor and battery (15-25 lbs) means a smaller frame is easier to control, especially at low speeds and when stopping.
How do I measure my inseam for bike sizing?
Stand against a wall in bare feet with a book held firmly between your legs (spine up, simulating a saddle). Measure from the top of the book to the floor. This is your cycling inseam, which may differ slightly from your trouser inseam.
Do all e-bike brands use the same sizing?
No. Sizing varies between brands and even between models within the same brand. Some brands like Rad Power Bikes use a one-size-fits-most approach, while others like Specialized and Trek offer 4-5 distinct frame sizes. Always refer to the specific brand’s size chart and, ideally, test ride before buying.