{"schema":"askedwell-earned-page-v1","url":"https://askedwell.com/pages/how-to-convert/fahrenheit-to-celsius","question":"How do I convert fahrenheit to celsius?","short_answer":"Exact formula: °C = (°F − 32) × 5/9. Quick approximation: subtract 30 then halve (°C ≈ (°F − 30) ÷ 2). Common cooking: 350°F = 177°C; 400°F = 205°C; 425°F = 218°C; 165°F (poultry safe) = 74°C; 32°F (freezing) = 0°C; 212°F (boiling) = 100°C.","long_answer":"**The formula**\n\n**Exact:** °C = (°F − 32) × 5/9\nOr equivalently: °C = (°F − 32) ÷ 1.8\n\n**Quick mental math:** °C ≈ (°F − 30) ÷ 2\n- Accurate within ~2°C for most kitchen temperatures\n- Easy to do in your head while cooking\n\n**Reverse direction:** °F = (°C × 9/5) + 32, or °F = (°C × 1.8) + 32\n\n**Where the formula comes from**\n\nDaniel Gabriel Fahrenheit (1724) calibrated his scale so 0°F = a brine mixture's freezing point and 96°F = \"blood-warm\" (his estimate of body temp; actually 98.6°F).\n\nAnders Celsius (1742) calibrated: 0°C = water freezes; 100°C = water boils (at sea level). His original scale was inverted (0 = boil); Linnaeus flipped it in 1745.\n\nThe conversion is a linear transformation: F and C scales share the same physical reality but with different zero points (freezing offset by 32) and different unit sizes (1°F = 5/9 of 1°C).\n\n**Critical cooking temperatures (memorize these)**\n\n| Fahrenheit | Celsius | What it is |\n|---|---|---|\n| 32°F | 0°C | Water freezing |\n| 40°F | 4°C | Safe refrigerator temp |\n| 140°F | 60°C | Danger zone upper bound |\n| 145°F | 63°C | Safe internal: fish, beef medium-rare |\n| 160°F | 71°C | Safe internal: ground meat |\n| 165°F | 74°C | Safe internal: ALL poultry (USDA mandatory) |\n| 195°F | 90°C | Safe internal: dark-meat chicken (preferred) |\n| 200°F | 93°C | Safe internal: pork shoulder, brisket |\n| 212°F | 100°C | Water boiling (sea level) |\n| 250°F | 121°C | Slow cooking (BBQ low-and-slow) |\n| 300°F | 149°C | Low oven |\n| 325°F | 163°C | Moderate oven (cakes) |\n| 350°F | 177°C | Standard baking |\n| 375°F | 191°C | Bread, biscuits |\n| 400°F | 205°C | Roasting vegetables, pizza |\n| 425°F | 218°C | Crispy roasted things |\n| 450°F | 232°C | Pizza, broiling |\n| 500°F | 260°C | Pizza oven (modest) |\n| 550°F | 288°C | Max home oven |\n| 800°F | 427°C | Wood-fired pizza |\n| 900°F | 482°C | Steel-grate-shut grill |\n\n**Common rookie mistakes**\n\n- Forgetting the 32 offset (just multiplying by 5/9 gives wildly wrong results)\n- Confusing direction (F→C uses subtract-then-multiply; C→F uses multiply-then-add)\n- Using approximation for sensitive cooking (sourdough proofing, custards, ganache) — use exact formula\n- Confusing oven dial markings: many US ovens use Fahrenheit; EU/UK ovens use Celsius. Check before recipe-following!\n\n**Cross-reference:** see /pages/how-to-convert/celsius-to-fahrenheit for reverse direction + /pages/what-temperature-for/baking-bread for baking-specific temps.","ranges":[{"condition":"Exact formula","duration":"°C = (°F − 32) × 5/9"},{"condition":"Quick mental math","duration":"°C ≈ (°F − 30) ÷ 2","note":"Within ~2°C"},{"condition":"Critical: poultry safe","duration":"165°F = 74°C"},{"condition":"Water freezing","duration":"32°F = 0°C"},{"condition":"Standard baking","duration":"350°F = 177°C"},{"condition":"Water boiling (sea level)","duration":"212°F = 100°C"},{"condition":"Pizza oven","duration":"500°F = 260°C"},{"condition":"Wood-fired pizza","duration":"800°F = 427°C"}],"variables":[{"name":"Direction (F to C vs C to F)","effect":"F to C: subtract 32 first, then multiply by 5/9. C to F: multiply by 9/5 first, then add 32."},{"name":"Approximation vs exact","effect":"For oven temps ±5°C tolerance: approximation OK. For ganache, custards, ferments: use exact."},{"name":"Altitude (boiling point)","effect":"Water boils at 212°F (100°C) at sea level only. -1°F (-0.5°C) per 1000ft altitude."},{"name":"Oven calibration","effect":"Most home ovens are off ±25°F (±14°C). Use an oven thermometer; convert AFTER calibration."},{"name":"Conversion app vs mental math","effect":"Use phone for precision-critical recipes (custards, soufflés). Mental math fine for roasting + most baking."}],"sources":[{"label":"NIST (National Institute of Standards + Technology)","url":"https://www.nist.gov/pml/owm/metric-si/length-volume-temperature-conversion-tables","note":"Authoritative conversion factors"},{"label":"USDA FSIS Safe Minimum Cooking Temperatures","url":"https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/safe-temperature-chart","note":"Critical food-safety temps in both units"},{"label":"King Arthur Baking temperature conversion chart","url":"https://www.kingarthurbaking.com/learn/resources/oven-temperature-conversion","note":"Baking-specific conversion table"},{"label":"BIPM (International Bureau of Weights + Measures)","note":"Official SI unit definitions for Celsius (kelvin-based)"}],"faq":[{"question":"Why does the formula use 5/9 instead of 5/8?","answer":"Because the Fahrenheit scale has 180 degrees between water's freezing (32°F) and boiling (212°F), while the Celsius scale has only 100 degrees between freezing (0°C) and boiling (100°C). The ratio is 100/180 = 5/9. So 1°F is exactly 5/9 of 1°C. The offset of 32 accounts for where the freezing point sits in each scale. Using 5/8 would give an answer ~12% too high."},{"question":"Can I just halve the fahrenheit number to get celsius?","answer":"Only approximately — and only after subtracting 30. The shortcut °C ≈ (°F − 30) ÷ 2 is accurate within ~2°C for most kitchen temperatures (300-450°F range). For 350°F: shortcut gives (350-30)/2 = 160°C; actual is 177°C. The shortcut is off by 17°C here — fine for \"roughly preheat\" but not for ganache (1°C off ruins texture). For precision, always use the exact formula or a phone app."},{"question":"My recipe says 180°C — what is that in fahrenheit?","answer":"180°C = 356°F. This is the European/UK standard for \"moderate oven\" — equivalent to American \"350°F\" recipes. The 6°F difference is generally within oven calibration tolerance, so following 180°C as 350°F in your American oven is fine. Other common European temps: 160°C = 320°F (slow); 200°C = 392°F ≈ 400°F (hot); 220°C = 428°F ≈ 425°F (very hot)."}],"keywords":["fahrenheit to celsius","F to C conversion","oven temperature conversion","cooking temperature converter","celsius fahrenheit formula"],"category":"cooking","date_published":"2026-05-20","date_modified":"2026-05-20","license":"CC-BY-4.0","attribution":"https://askedwell.com"}