Kevelin recommendation engine
How Much CADR Does Your Room Need?
Tell us about your room and air quality. KEVELIN will calculate the recommended CADR and help you choose the right air purifier.
Air purifier CADR calculator
Your room
Enter the internal dimensions. We convert units for you.
Room area
120 sq ft
11.15 m²
Room volume
30.58 m³
1080 ft³
Room volume matters because a room with a higher ceiling contains more air even if the floor area is the same.
What type of room is this?
Is your room:
Your name
We add your name to your shareable air report card.
How many people normally use this room?
More occupants can increase the recommended purification capacity.
How long will you use the purifier each day?
Where is your home located?
What is the current outdoor AQI?
What are you mainly concerned about?
Select all that apply.
How often are doors/windows open?
Outdoor air entering the room can continuously introduce new pollutants.
How quickly do you want your room purified?
What is your target?
Your CADR
242m³/h
Range 218–266 m³/h · 5 ACH
95% accuracy
- Your room
- 120 sq ft
- Volume
- 30.58 m³
- People
- 2
- AQI
- Very Poor
The result updates as you change inputs. Press Calculate to see the full recommendation, model match and share options.
What Is CADR?
CADR stands for Clean Air Delivery Rate. It indicates the rate at which an air purifier delivers cleaned air.
Why CADR Matters
Higher CADR generally means more clean-air delivery capacity — which lets a purifier keep up with a bigger room, a higher ceiling or dirtier outdoor air.
Room Size Isn't Enough
Room A
- 120 sq ft
- 8 ft ceiling
- AQI 70
- 1 person
Room B
- 120 sq ft
- 12 ft ceiling
- AQI 300
- 3 people
- Frequent outdoor air exchange
Both rooms have the same floor area, but their air-purification requirements can be different.
CADR calculator FAQs
What is CADR?
CADR stands for Clean Air Delivery Rate. It indicates the rate — usually in m³/h — at which an air purifier delivers cleaned air. A higher CADR generally means more clean-air delivery capacity.
How much CADR do I need for a 100 sq ft room?
A 100 sq ft room with a 9 ft ceiling is roughly 25 m³. At 5 air changes per hour that is about 125 m³/h before adjustments for AQI, ventilation and occupancy, which typically push it to 150–190 m³/h in Indian cities.
How much CADR do I need for a 200 sq ft room?
A 200 sq ft room with a 9 ft ceiling is roughly 51 m³. At 5 air changes per hour that is about 255 m³/h before adjustments — commonly 300–380 m³/h in high-AQI conditions.
Is higher CADR better?
A higher CADR gives you faster clean-air delivery and lets you run the purifier at a lower, quieter speed. It is not always necessary — matching CADR to your room volume and conditions is the practical goal.
What is ACH?
ACH means Air Changes per Hour — approximately how many times the equivalent volume of room air is processed in an hour.
How is CADR calculated?
Required CADR = room volume (m³) × target ACH, then adjusted for outdoor AQI, ventilation, occupancy, room type, location, pollution concerns and room shape.
Does ceiling height affect CADR?
Yes. Room volume, not floor area, determines how much air must be processed. A 12 ft ceiling holds 50% more air than an 8 ft ceiling over the same floor area.
Does AQI affect purifier requirements?
Higher outdoor AQI generally means more particulate entering the room, so a higher clean-air delivery rate is usually recommended.
Do I need one or two air purifiers?
If your required CADR is well above a single unit's capacity, or the space is L-shaped, open-plan or split across connected rooms, two units can improve both capacity and air distribution. Two units do not always behave exactly like one purifier with the combined CADR.
Is room-size coverage the same as CADR?
No. Coverage claims assume a fixed ceiling height and air-change target. CADR is the measured delivery rate and is the more reliable number to compare.
How long does an air purifier take to clean a room?
Theoretically, one air change takes 60 ÷ ACH minutes. This is an estimate — real rooms leak air and pollutants keep entering.
What CADR is suitable for a bedroom?
Most Indian bedrooms of 100–150 sq ft are well served by roughly 150–250 m³/h, depending on ceiling height, AQI and how often windows are open.
What CADR is suitable for a living room?
Living rooms of 200–350 sq ft usually need roughly 300–500 m³/h, often best delivered by two well-placed units.
Does keeping windows open affect purifier performance?
Yes. Open windows continuously bring in outdoor air, so the purifier has to work harder to hold indoor particulate down.
Give Your Room the CADR It Deserves.
Now that you know your room's requirement, find the KEVELIN purifier built for it.
CADR recommendations are estimates based on the information provided and are intended for consumer guidance. Actual air-cleaning performance can vary depending on room layout, air leakage, outdoor-air infiltration, purifier placement, operating speed, filter condition and other factors. This calculator is not medical advice and does not guarantee a specific indoor AQI.