What Size Chainsaw Do I Need?
Your chainsaw bar should be at least 2 inches longer than the diameter of what you're cutting. A 16-inch bar cuts logs up to 14 inches in a single pass. An 18-inch bar handles up to 16 inches. For most homeowners, a 16-to-18-inch bar covers 90% of tasks. Use our quick-reference table below to match your cutting task to the right bar length.
Not sure which chainsaw? Try our Cut Calculator — 4 questions, one recommendation.
Bar Length Guidance
Rule of thumb: bar length = log diameter + 2 inches, rounded up to the nearest standard size (10", 12", 14", 16", 18", 20").
Bar length is the single most important spec when choosing a chainsaw. Too short and you can't finish cuts in one pass, forcing dangerous re-positioning. Too long and you're carrying extra weight you don't need, with more bar to control and a higher kickback risk.
The rule is simple: your bar should be at least 2 inches longer than the diameter of what you're cutting. A 14-inch log needs a 16-inch bar minimum. An 18-inch round needs a 20-inch bar. This gives clearance for the chain to pass completely through without the nose contacting the ground or pinching.
Can you cut something bigger than your bar? Yes, with a technique called bore cutting or cutting from both sides. But it's slower, requires experience, and increases the risk of pinching. Match your bar to your typical cutting task, and you'll rarely need to bore cut.
The most common chainsaw bar length is 18 inches. It's the universal homeowner size: big enough for firewood and small tree felling, short enough to control safely. If you could only own one chainsaw, an 18-inch bar is the answer.
Bar Length Quick Reference
| What You're Cutting | Typical Diameter | Minimum Bar | Recommended Bar | Guide |
|---|---|---|---|---|
| Small branches & pruning | Under 6" | 8" | 10"-12" | Best picks |
| Large branches & limbing | 6"-10" | 10" | 12"-14" | Best picks |
| Small tree removal | 8"-12" | 12" | 14"-16" | Best picks |
| Firewood from rounds | 10"-16" | 14" | 16"-18" | Best picks |
| Medium tree felling | 14"-20" | 18" | 18"-20" | Best picks |
| Large tree felling | 20"+ | 22" | 24"+ (hire a pro) | Best picks |
Frequently Asked Questions
- What size chainsaw do I need?
- Match bar length to your typical cutting task. For pruning (under 6" branches): 10-12" bar. For storm cleanup (6-12" trunks): 14-16" bar. For firewood (10-16" rounds): 16-18" bar. For felling (14-20" trees): 18-20" bar. For large trees (20"+): 24" bar or hire an arborist. The rule of thumb: bar length = log diameter + 2 inches.
- What bar length do I need for firewood?
- An 18-inch bar is the sweet spot for firewood. Most firewood rounds are 10-16 inches in diameter. An 18-inch bar cuts a 16-inch round in a single pass. If your rounds are consistently under 12 inches, a 16-inch bar saves weight.
- Can I cut a tree bigger than my bar length?
- Yes, by cutting from both sides or using a bore cut (plunging the bar into the wood). Both techniques are slower and require experience. Bore cutting increases kickback risk and should only be attempted by experienced operators. For regular cutting, match your bar to the task.
- What happens if my chainsaw bar is too short?
- You'll need to cut from multiple angles to get through the wood. This is slower, increases the risk of the chain pinching in the cut, and forces awkward body positions. A bar that's 2+ inches longer than your typical log diameter lets you cut cleanly in one pass.
- What's the most common chainsaw bar length?
- 18 inches is the most popular bar length. It's the universal homeowner size: big enough for firewood rounds up to 16 inches and small tree felling, short enough to control safely. If you're buying one chainsaw for general property maintenance, start with 18 inches.