Area and Taiwan ping
Convert area between square metres, square feet and Taiwan ping. This is an area conversion rather than a judgement about property records.
Understand the numbers · Make life easier
CADR and air-cleaner room area calculator
Convert particle CADR, its unit, ceiling height and assumed clean-air cycles into a comparison area, not a guaranteed room rating.
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Comparison area under your assumptions (not a guaranteed rating)
6.48Taiwan ping
The answer is an area calculated from your assumptions, not a certified room-size rating or health guarantee. Taiwan ping and square metres are shown together. Fan speed, filters, placement and partitions affect actual performance; an air cleaner does not replace ventilation.
The same comparison area21.43 m²
Particle CADR converted to hourly units300 m³/h
Equivalent room volume60 m³
Entered clear ceiling height2.8 m
Entered assumed equivalent clean-air cycles5 cycles/hour
Worked steps
- 300 ÷ 5 ≈ 60
- 60 ÷ 2.8 ≈ 21.43
- 21.43 × 121 ÷ 400 ≈ 6.48
Formula: convert CFM to m³/h by multiplying by 0.3048³ × 60. Equivalent volume = CADR divided by assumed cycles/hour. Area = volume divided by height. One Taiwan ping is 400/121 m². Keep unrounded values until display. Ordinary areas display two decimal places; very small positive values retain up to eight to avoid false zero. Display precision is not measurement or performance accuracy. CADR already accounts for particle removal efficiency; do not multiply by filter efficiency again. Use the same particle rating and fan speed under an ideal mixing assumption. Do not mix smoke, dust and pollen ratings. This does not model outdoor air, doors, ongoing sources or flow between rooms, predict complete cleaning time, or guarantee gas or CO₂ removal, infection prevention or allergy relief. Follow manufacturer guidance, professional assessment and applicable rules for the setting.
Method and scope
Formula: convert CFM to m³/h by multiplying by 0.3048³ × 60. Equivalent volume = CADR divided by assumed cycles/hour. Area = volume divided by height. One Taiwan ping is 400/121 m². Keep unrounded values until display.
Ordinary areas display two decimal places; very small positive values retain up to eight to avoid false zero. Display precision is not measurement or performance accuracy. CADR already accounts for particle removal efficiency; do not multiply by filter efficiency again.
Use the same particle rating and fan speed under an ideal mixing assumption. Do not mix smoke, dust and pollen ratings. This does not model outdoor air, doors, ongoing sources or flow between rooms, predict complete cleaning time, or guarantee gas or CO₂ removal, infection prevention or allergy relief. Follow manufacturer guidance, professional assessment and applicable rules for the setting.
References:CDC: equivalent clean-air cycles and room-volume formula、EPA: particle CADR, fan speed and ventilation limitations、NIST: international foot and metre conversion
What this tool helps you do
Compare areas for a known particle CADR at different ceiling heights and assumed equivalent clean-air cycles. This tool does not select brands or certify room safety. Equivalent clean air from filtration is not the same as fresh outdoor ventilation.
What to enter
Enter the original CADR number and choose m³/h or CFM. Use metres for clear ceiling height. The assumed cycle rate must be positive. Confirm ratings in m³/min or unfiltered airflow before using them.
How it is calculated
Formula: convert CFM to m³/h by multiplying by 0.3048³ × 60. Equivalent volume = CADR divided by assumed cycles/hour. Area = volume divided by height. One Taiwan ping is 400/121 m². Keep unrounded values until display.
Worked example
Synthetic example: 420 m³/h, a 2.8 m ceiling and 5 assumed cycles/hour give 420 ÷ 5 = 84 m³, then 84 ÷ 2.8 = 30 m², or 30 × 121 ÷ 400 = 9.075 ping, displayed as about 9.08 ping.
Understanding the answer
Ordinary areas display two decimal places; very small positive values retain up to eight to avoid false zero. Display precision is not measurement or performance accuracy. CADR already accounts for particle removal efficiency; do not multiply by filter efficiency again.
Scope and limitations
Use the same particle rating and fan speed under an ideal mixing assumption. Do not mix smoke, dust and pollen ratings. This does not model outdoor air, doors, ongoing sources or flow between rooms, predict complete cleaning time, or guarantee gas or CO₂ removal, infection prevention or allergy relief. Follow manufacturer guidance, professional assessment and applicable rules for the setting.