Indoor air can hold five times more pollutants than the air outside, and most of that grime starts at your stove. When the range hood can’t move enough cubic feet of air, smoke and grease drift through the rest of the house, coating walls and lungs alike.
That’s why every cook eventually asks what is the best cfm for range hood. In the next few minutes I’ll walk you through a simple, numbers-first roadmap that nails the right CFM for your kitchen and avoids common, costly mistakes.
Keynote: What Is the Best CFM for Range Hood?
Calculate CFM, don’t guess. Gas: total BTU ÷ 100. Electric: width × 10 (wall) or × 15 (island). Volume ÷ 4 baseline. Add duct losses. Over 400 CFM needs makeup air; 400–600 CFM fits most kitchens.
How to Calculate Your Ideal CFM
Step 1 – Match the Stove
| Gas Stove BTU (total) | Minimum CFM* |
|---|---|
| 30 000 BTU | 300 CFM |
| 50 000 BTU | 500 CFM |
| 70 000 BTU | 700 CFM |
| 100 000 BTU | 1000 CFM |
*Rule of thumb: 100 CFM per 10 000 BTU.
| Electric / Induction Width | Wall / Cabinet Range Hood | Island Hoods |
|---|---|---|
| 24-inch range | 240 CFM | 360 CFM |
| 30-inch range | 300 CFM | 450 CFM |
| 36-inch range | 360 CFM | 540 CFM |
Multiply width (inches) by 10 for wall hoods or 15 for island hoods.
Step 2 – Size of Your Kitchen
- Find the volume of air: Length × Width × Height.
- Divide by 4.
- That number equals the lowest CFM your kitchen exhaust fan should ever pull.
Example: A 15 × 10 × 8 ft space holds 1 200 cubic feet; 1 200 ÷ 4 = 300 CFM.
Step 3 – Adjust for Cooking Style
Add 100–200 CFM if you love stir-fries, deep-frying, or spicy dishes that blanket the cooking area in vapors. Heavy wok nights? Bump the cfm rating higher still.
Hidden Factors That Inflate CFM Needs
Ductwork Obstacles
- Add 1 CFM per linear foot of duct.
- Add 25 CFM per 90° bend.
- Add 40 CFM for a roof or wall cap.
Smooth, rigid stainless-steel duct keeps static pressure low and noise down.
Hood Mount & Type of Range Hood
- Under-cabinet: plan on 100 CFM per linear foot of cooking surface.
- Island hoods sit in open air, so use 150 CFM per foot.
- Downdraft designs fight rising heat and need an even higher CFM model.
Open-Concept or Larger Kitchen
Big rooms dilute fumes, so a higher CFM rating prevents lingering odors in the kitchen air and beyond.
Avoiding Classic CFM Mistakes
- Lower CFM than needed leaves grease on cabinets and hurts indoor air quality.
- Higher CFM than planned can roar above 65 dB, waste power, and create negative pressure that drags in cold air without makeup air systems >400 CFM.
- Ignoring duct diameter chokes the ventilation system. A 400-CFM hood needs at least a 6-inch duct; 900 CFM loves 8-inch.
- Local codes may demand makeup air when any hood CFM breaks that 400-CFM line.
Balancing Power with Practicality
Noise and Fan Speeds
The Home Ventilating Institute urges buyers to choose hoods under 3 sones at 200 CFM for quiet operation. Pick fan speeds you can actually stand; use lower speeds for simmering and reserve high CFM blasts for searing steaks.
Energy & Air Exchanges
Every CFM of warm kitchen air you expel drags in the same volume of outside air, forcing HVAC systems to re-heat or re-cool that volume of air. Variable motors and auto-shutoff timers trim the bill.
Ducted vs. Ductless – Which Way to Vent?
| Feature | Ducted | Ductless (Recirculation Kit) |
|---|---|---|
| Removes heat, humidity, grease | Yes | No (filters only) |
| Ventilation power limit | High CFM possible | Lower CFM preferred |
| Maintenance | Clean filters + ducts | Replace charcoal filters often |
| Best for | Heavy gas stove users, island range cooks | Apartments, remodels without outside ventilation |
Whenever feasible, a ducted quality range hood beats even the most powerful range hoods that simply recirculate.
Top CFM Picks by Scenario
| Kitchen & Stove | Recommended Rated CFM | Example** |
|---|---|---|
| Small electric cooktop, 24-inch | 250–350 CFM | 250 CFM cabinet range hood |
| Standard gas stove, 30-inch | 400–600 CFM | 450 CFM wall unit |
| Large open plan, 48-inch pro range | 900–1 500 CFM | 1 200 CFM island canopy |
Match CFM to calculations first; models shown are illustrative. *Look for HVI-certified labels, solid baffle filters, and quiet operation under 7 sones.
Final Checklist & Pro Tips
- Run the final calculation: highest value among BTU, width, and room volume.
- Add duct penalties; round up to the next cfm number.
- Verify duct diameter and plan shortest run.
- If target > 400 CFM, budget for makeup air.
- Choose a hood with multi-speed controls, LED lights, and at least one good idea—like delayed shutoff.
A slightly higher cfm hood, run at lower speeds, often supplies perfect headroom for holiday feasts while staying hushed on Wednesday pasta nights.
Conclusion – Putting It All Together
The ideal what is the best cfm for range hood isn’t a magic digit; it’s the sum of stove BTU, room volume, duct design, and your unique kitchen habits. Follow the numbers and you’ll land on a right range hood that clears smoke fast without howling like a jet.
Treat your hood like the kitchen’s lungs. Size it wisely, vent it properly, and it will quietly pull harmful fumes outside while you savor every sizzle inside. Your future self—and your air quality—will thank you.
Best Cfm for Range Hood (FAQs)
How many cfm is good for a range hood?
Most kitchens perform well with 400–600 CFM, balancing strong ventilation with manageable noise and energy demands. Use 100 CFM per cooktop foot or total BTU ÷ 100 to refine your target precisely.
Is 400 cfm enough for a gas range?
400 CFM handles most 40–50 k BTU gas ranges when ducts are short and the hood is mounted correctly. Add 100–200 CFM for frequent frying, extended ducts, or BTU totals above sixty thousand daily.
Does a 400 cfm range hood need make up air?
Building codes trigger mandatory makeup air when exhaust exceeds 400 CFM, preventing dangerous negative house pressure. At exactly 400 CFM, many jurisdictions waive the requirement, yet local inspectors still decide final compliance.
Is 1200 cfm a lot?
Yes, 1200 CFM ranks among high-power residential hoods, suited to 48-inch pro ranges and heavy wok cooking. Such airflow always demands large eight-inch ducts, extra noise control, and code-approved makeup air systems.
Katie Lee has over 20 years of experience in the kitchen. She helps homeowners find the right appliances for their needs to sets up a perfect kitchen system. She also shares helpful tips and tricks for optimizing appliance performance.