Free reference
Density Altitude Chart
DA by air temperature and station pressure, at three humidities. Find your row and column, read the number.
What is the density altitude for my temperature and pressure?
Find your air temperature on the left and your station pressure across the top. The number where they meet is density altitude in feet, rounded to the nearest 10. Station pressure is what a Kestrel or a track meter reads; if you only have a weather report, convert the altimeter setting first.
| Air °F | 24.0″ | 24.5″ | 25.0″ | 25.5″ | 26.0″ | 26.5″ | 27.0″ | 27.5″ | 28.0″ | 28.5″ | 29.0″ | 29.5″ | 30.0″ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 40°F | 6,170 | 5,500 | 4,830 | 4,170 | 3,530 | 2,890 | 2,260 | 1,640 | 1,030 | 430 | -160 | -750 | -1,330 |
| 50°F | 6,830 | 6,160 | 5,500 | 4,840 | 4,200 | 3,570 | 2,940 | 2,330 | 1,720 | 1,120 | 530 | -60 | -630 |
| 60°F | 7,490 | 6,820 | 6,150 | 5,500 | 4,860 | 4,230 | 3,610 | 3,000 | 2,390 | 1,790 | 1,200 | 620 | 50 |
| 70°F | 8,130 | 7,460 | 6,800 | 6,160 | 5,520 | 4,890 | 4,270 | 3,660 | 3,050 | 2,460 | 1,870 | 1,290 | 720 |
| 80°F | 8,770 | 8,100 | 7,450 | 6,800 | 6,170 | 5,540 | 4,920 | 4,310 | 3,710 | 3,120 | 2,530 | 1,960 | 1,390 |
| 90°F | 9,410 | 8,740 | 8,090 | 7,450 | 6,810 | 6,190 | 5,570 | 4,960 | 4,360 | 3,770 | 3,190 | 2,620 | 2,050 |
| 100°F | 10,050 | 9,380 | 8,730 | 8,090 | 7,460 | 6,830 | 6,220 | 5,620 | 5,020 | 4,430 | 3,850 | 3,280 | 2,710 |
| 110°F | 10,690 | 10,030 | 9,380 | 8,740 | 8,110 | 7,490 | 6,870 | 6,270 | 5,680 | 5,090 | 4,510 | 3,940 | 3,370 |
| Air °F | 24.0″ | 24.5″ | 25.0″ | 25.5″ | 26.0″ | 26.5″ | 27.0″ | 27.5″ | 28.0″ | 28.5″ | 29.0″ | 29.5″ | 30.0″ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 40°F | 6,210 | 5,530 | 4,860 | 4,200 | 3,560 | 2,920 | 2,290 | 1,670 | 1,060 | 460 | -130 | -720 | -1,300 |
| 50°F | 6,880 | 6,210 | 5,540 | 4,890 | 4,240 | 3,610 | 2,980 | 2,370 | 1,760 | 1,160 | 570 | -20 | -590 |
| 60°F | 7,550 | 6,880 | 6,220 | 5,570 | 4,930 | 4,290 | 3,670 | 3,060 | 2,450 | 1,850 | 1,260 | 680 | 110 |
| 70°F | 8,220 | 7,550 | 6,900 | 6,250 | 5,610 | 4,980 | 4,350 | 3,740 | 3,140 | 2,540 | 1,950 | 1,370 | 800 |
| 80°F | 8,900 | 8,230 | 7,570 | 6,930 | 6,290 | 5,660 | 5,040 | 4,430 | 3,830 | 3,230 | 2,650 | 2,070 | 1,500 |
| 90°F | 9,590 | 8,920 | 8,260 | 7,620 | 6,980 | 6,350 | 5,740 | 5,130 | 4,530 | 3,930 | 3,350 | 2,770 | 2,200 |
| 100°F | 10,290 | 9,630 | 8,970 | 8,320 | 7,690 | 7,060 | 6,440 | 5,840 | 5,240 | 4,640 | 4,060 | 3,480 | 2,920 |
| 110°F | 11,020 | 10,350 | 9,700 | 9,050 | 8,420 | 7,790 | 7,180 | 6,570 | 5,970 | 5,380 | 4,790 | 4,220 | 3,650 |
| Air °F | 24.0″ | 24.5″ | 25.0″ | 25.5″ | 26.0″ | 26.5″ | 27.0″ | 27.5″ | 28.0″ | 28.5″ | 29.0″ | 29.5″ | 30.0″ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 40°F | 6,240 | 5,560 | 4,890 | 4,240 | 3,590 | 2,950 | 2,320 | 1,700 | 1,090 | 490 | -110 | -690 | -1,270 |
| 50°F | 6,930 | 6,250 | 5,590 | 4,930 | 4,290 | 3,650 | 3,030 | 2,410 | 1,800 | 1,200 | 610 | 20 | -550 |
| 60°F | 7,620 | 6,950 | 6,280 | 5,630 | 4,990 | 4,360 | 3,730 | 3,120 | 2,510 | 1,910 | 1,320 | 740 | 160 |
| 70°F | 8,320 | 7,650 | 6,990 | 6,340 | 5,700 | 5,060 | 4,440 | 3,830 | 3,220 | 2,620 | 2,040 | 1,450 | 880 |
| 80°F | 9,030 | 8,360 | 7,700 | 7,050 | 6,410 | 5,780 | 5,160 | 4,550 | 3,950 | 3,350 | 2,760 | 2,180 | 1,610 |
| 90°F | 9,770 | 9,100 | 8,440 | 7,790 | 7,150 | 6,520 | 5,900 | 5,290 | 4,690 | 4,090 | 3,500 | 2,930 | 2,350 |
| 100°F | 10,540 | 9,870 | 9,210 | 8,560 | 7,920 | 7,290 | 6,670 | 6,060 | 5,450 | 4,860 | 4,270 | 3,690 | 3,120 |
| 110°F | 11,350 | 10,680 | 10,020 | 9,370 | 8,730 | 8,100 | 7,480 | 6,860 | 6,260 | 5,670 | 5,080 | 4,500 | 3,930 |
Calculated with the same virtual-temperature formula the app uses on every pass. Humid air is less dense than dry air, so the same temperature and pressure give a higher DA at higher humidity.
Which pressure column is my track?
On a standard day (59°F and 29.92″ at sea level) station pressure drops as elevation goes up. Use this to find your column before race day; the real reading moves with the weather.
| Track elevation | Standard-day station pressure |
|---|---|
| 0 ft | 29.92″ |
| 1,000 ft | 28.85″ |
| 2,000 ft | 27.82″ |
| 3,000 ft | 26.82″ |
| 4,000 ft | 25.84″ |
| 5,000 ft | 24.90″ |
| 6,000 ft | 23.98″ |
| 7,000 ft | 23.09″ |
How do I read the chart?
Read across a row and DA falls as pressure rises. Read down a column and DA rises with heat. A hot afternoon can put a sea-level track at a DA higher than a mountain track on a cool morning.
How much a car slows per 1,000 ft of DA is different for every car. The ET predictor learns it from your own passes, and the density altitude guide explains the air in more depth.
Want the DA for every pass without a chart?
The free logbook saves temperature, humidity, station pressure, wind and DA from the closest weather station the moment you log a pass.