Educational only — verify against packaging and professional advice
These are dense, at-hand numbers for moments when the original label, manual, or almanac is gone. Critical values — especially medicine doses — must be checked against actual packaging or a professional. The medication tables mirror Medical: Dosing by Weight, which links here.
Water treatment
Unscented liquid bleach in clear water — stir, wait 30 minutes; a slight chlorine smell means success. Double the drops if cloudy (after settling/filtering).
| Bleach strength | Drops per gallon | Drops per quart |
|---|
| 6% sodium hypochlorite (regular) | 8 drops | 2 drops |
| 8.25% sodium hypochlorite (“concentrated”/ultra) | 6 drops | 2 drops (rounded down) |
Rolling boil = bubbles you cannot stir away
| Altitude | Time at rolling boil |
|---|
| Below 6,500 ft / 2,000 m | 1 full minute |
| Above 6,500 ft / 2,000 m | 3 full minutes |
Purification tablets: dosing and contact time vary by brand. Most chlorine-dioxide tablets treat 1 liter in about 30 minutes; Cryptosporidium can demand up to 4 hours. The printed directions are the authority — expired tablets lose strength.
Medication dosing by weight
Dose by weight, never age, whenever the weight is known. Full rules, cautions, and adult notes live at Dosing by Weight. Never kitchen spoons — use the device from the box.
Acetaminophen — children’s liquid 160 mg / 5 mL
| Weight | Liquid (160 mg / 5 mL) | Frequency | Max in 24 h |
|---|
| Under 12 lb / 5 kg | Ask a professional — do not guess | — | — |
| 12–17 lb / 5–7 kg | 2.5 mL | Every 4–6 h | 5 doses |
| 18–23 lb / 8–10 kg | 3.75 mL | Every 4–6 h | 5 doses |
| 24–35 lb / 11–15 kg | 5 mL | Every 4–6 h | 5 doses |
| 36–47 lb / 16–21 kg | 7.5 mL | Every 4–6 h | 5 doses |
| 48–59 lb / 22–26 kg | 10 mL | Every 4–6 h | 5 doses |
| 60–71 lb / 27–32 kg | 12.5 mL | Every 4–6 h | 5 doses |
| 72–95 lb / 33–43 kg | 15 mL | Every 4–6 h | 5 doses |
| 96 lb+ / 44 kg+ | 20 mL, or 1–2 regular-strength tablets (325 mg each) | Every 4–6 h | 5 doses |
| No aspirin under 19 during viral illness — risk of Reye’s syndrome. Applies to both medicines on this page. |
Ibuprofen — infants’/children’s liquid 100 mg / 5 mL · ages 6 months and up only · give with food if possible
| Weight | Liquid (100 mg / 5 mL) | Frequency | Max in 24 h |
|---|
| Under 6 months old | Not without professional direction | — | — |
| Under 12 lb / 5 kg | Ask a professional — do not guess | — | — |
| 12–17 lb / 5–7 kg | 2.5 mL | Every 6–8 h | 4 doses |
| 18–23 lb / 8–10 kg | 3.75 mL | Every 6–8 h | 4 doses |
| 24–35 lb / 11–15 kg | 5 mL | Every 6–8 h | 4 doses |
| 36–47 lb / 16–21 kg | 7.5 mL | Every 6–8 h | 4 doses |
| 48–59 lb / 22–26 kg | 10 mL | Every 6–8 h | 4 doses |
| 60–71 lb / 27–32 kg | 12.5 mL | Every 6–8 h | 4 doses |
| 72–95 lb / 33–43 kg | 15 mL | Every 6–8 h | 4 doses |
| 96 lb+ / 44 kg+ | 20 mL, or 1 tablet (200 mg) | Every 6–8 h | 4 doses |
Fuel mix ratios
Two-cycle (2-stroke) engines only — premix in a labeled can, shake to blend, mix fresh each season.
| Ratio (gas:oil) | Oil per 1 gal gasoline | Oil per 1 liter gasoline |
|---|
| 50:1 | 2.6 fl oz | 20 mL |
| 40:1 | 3.2 fl oz | 25 mL |
| 32:1 | 4 fl oz | 31 mL |
Seed spacing
Typical USDA/extension-chart figures — the variety printed on your seed packet always wins.
| Vegetable | Sow depth | Thin to spacing | Rows apart | Days to harvest |
|---|
| Bush beans | 1 in | 2–4 in | 18–24 in | 50–60 |
| Beets | 1/2 in | 2–4 in | 12–18 in | 50–60 |
| Carrots | 1/4–1/2 in | 2–3 in | 12–18 in | 65–80 |
| Sweet corn | 1–2 in | 8–12 in | 30–36 in | 70–90 |
| Cucumbers | 1/2–1 in | 12 in | 36–60 in | 50–65 |
| Kale | 1/4–1/2 in | 8–12 in | 18–30 in | 55–65 |
| Leaf lettuce | 1/4 in | 6–8 in | 12–18 in | 40–55 |
| Onions | 1/4–1/2 in | 3–4 in | 12–18 in | 90–120 |
| Peas | 1–2 in | 1–2 in | 18–24 in | 55–70 |
| Peppers (transplant) | 1/4 in seed | 18–24 in | 24–36 in | 65–80 |
| Radishes | 1/4–1/2 in | 1–2 in | 6–12 in | 22–35 |
| Spinach | 1/2 in | 3–4 in | 12–18 in | 40–50 |
| Summer squash | 1 in | 24 in | 36–48 in | 50–60 |
| Tomatoes (transplant) | 1/4 in seed, set deep | 24–36 in | 36–48 in | 60–85 |
FRS/GMRS channels
FRS and GMRS share these frequencies — any consumer radio reaches any channel; only the legal power limits differ.
| Channel | Frequency (MHz) | FRS max power | GMRS max power |
|---|
| 1 | 462.5625 | 2 W | 5 W |
| 2 | 462.5875 | 2 W | 5 W |
| 3 | 462.6125 | 2 W | 5 W |
| 4 | 462.6375 | 2 W | 5 W |
| 5 | 462.6625 | 2 W | 5 W |
| 6 | 462.6875 | 2 W | 5 W |
| 7 | 462.7125 | 2 W | 5 W |
| 8 | 467.5625 | 0.5 W | Not permitted |
| 9 | 467.5875 | 0.5 W | Not permitted |
| 10 | 467.6125 | 0.5 W | Not permitted |
| 11 | 467.6375 | 0.5 W | Not permitted |
| 12 | 467.6625 | 0.5 W | Not permitted |
| 13 | 467.6875 | 0.5 W | Not permitted |
| 14 | 467.7125 | 0.5 W | Not permitted |
| 15 | 462.5500 | 2 W | 50 W |
| 16 | 462.5750 | 2 W | 50 W |
| 17 | 462.6000 | 2 W | 50 W |
| 18 | 462.6250 | 2 W | 50 W |
| 19 | 462.6500 | 2 W | 50 W |
| 20 | 462.7000 | 2 W | 50 W |
| 21 | 462.7500 | 2 W | 50 W |
| 22 | 462.7750 | 2 W | 50 W |
| Convention, not law: Channel 1 is the informal nationwide calling/travel channel — listen first, keep calls brief, then move to a working channel. Channel 3 is a widely mentioned prepper/community emergency-liaison habit; no channel carries any official emergency assignment. |
| License: FRS needs none. GMRS requires an FCC license — about $35, 10 years, no test, one license covers your immediate family. |
NOAA weather radio
All seven channels carry the same local National Weather Service broadcast — scan and stay on the clearest one.
| Preset | Frequency (MHz) |
|---|
| WX1 | 162.400 |
| WX2 | 162.425 |
| WX3 | 162.450 |
| WX4 | 162.475 |
| WX5 | 162.500 |
| WX6 | 162.525 |
| WX7 | 162.550 |
SAME/EAS: weather radios with SAME (Specific Area Message Encoding) can alarm only for chosen counties — look up your county’s 6-digit SAME code from the NWS before you need it and write it inside the radio’s battery door. Emergency Alert System messages ride this same network to broadcast stations.
Conversions
Volume — US customary to metric
| Unit | Equals | Metric equivalent |
|---|
| Teaspoon (tsp) | 1/3 tbsp | ≈ 5 mL |
| Tablespoon (tbsp) | 3 tsp | ≈ 15 mL |
| Fluid ounce (fl oz) | 2 tbsp | ≈ 30 mL |
| Cup | 8 fl oz = 16 tbsp | ≈ 237 mL |
| Pint (pt) | 2 cups | ≈ 473 mL |
| Quart (qt) | 4 cups | ≈ 946 mL |
| Gallon (gal) | 4 qt | ≈ 3.79 L |
| Liter (L) | 1000 mL | ≈ 34 fl oz |
Weight — US customary to metric
| Unit | Equals | Metric equivalent |
|---|
| Ounce (oz) | 1/16 lb | ≈ 28.3 g |
| Pound (lb) | 16 oz | ≈ 454 g |
| Gram (g) | 1/1000 kg | ≈ 0.035 oz |
| Kilogram (kg) | 1000 g | ≈ 2.2 lb |
Temperature — formulas
| Direction | Formula |
|---|
| Fahrenheit to Celsius | (°F − 32) × 5/9 |
| Celsius to Fahrenheit | (°C × 9/5) + 32 |
Temperature — landmarks worth memorizing
| Point | °F | °C |
|---|
| Water freezes | 32 | 0 |
| Normal body temperature | 98.6 | 37 |
| Fever threshold | 100.4 | 38 |
| Water boils (sea level) | 212 | 100 |
Distance — US customary to metric
| Unit | Equals | Metric equivalent |
|---|
| Inch (in) | — | = 2.54 cm |
| Foot (ft) | 12 in | ≈ 30.5 cm |
| Meter (m) | — | ≈ 3.28 ft |
| Mile (mi) | 5,280 ft | ≈ 1.61 km |
| Kilometer (km) | 1000 m | ≈ 0.62 mi |