28 Free Wilderness Survival Calculators — Works Offline, No Account 28 个免费野外生存计算器——离线可用，无需注册
Bleach drops for your bottle, wind-chill frostbite time, CPR tempo, bear-distance rules, real power-bank capacity in the cold and printable SAR trip plans — every result comes with the source and the math. 一瓶水该滴几滴漂白剂、风寒下多久冻伤、心肺复苏节拍、防熊距离、低温下充电宝真实容量、可打印的搜救行程单——每个结果都附出处与公式。
Browse by situation按场景浏览
Six hubs cover the decisions that actually happen on a trip.六个中枢覆盖出行中真正会遇到的决策。
Upgraded classic tools经典工具升级版
The four most-used calculators, rebuilt with sourced formulas, both unit systems and bilingual output.最常用的四个计算器全面重建：有出处的公式、英制公制双单位、中英双语结果。
Recently used
Pick up where you left off — saved on this device only.从上次离开处继续——仅保存在本设备。
Popular tools
The calculators hikers open before every trip and when weather turns.徒步者每次出发前、以及天气变坏时最常打开的计算器。
Field guides & survival scenarios野外指南与应急场景
15 original, bilingual deep dives — tutorials, data-driven comparisons and emergency playbooks.15 篇原创中英双语长文——教程、数据对比与应急处置手册。
What this toolkit calculates — and where the numbers come from本工具站算什么——数字从哪里来
Wilderness decisions are usually arithmetic under stress: drops of disinfectant, minutes of daylight, grams of fuel, meters of clearance. This site turns the arithmetic into instant, source-backed answers while you stand at a creek, a trailhead or a stormy ridge.
Water & Hydration
The water treatment dosing calculator implements U.S. CDC and EPA emergency-disinfection guidance for unscented household bleach (5.25–6% and 8.25%), 2% tincture of iodine and chlorine dioxide, including the cloudy-water doubling, cold-water contact-time penalty and the four-hour Cryptosporidium hold that chlorine and iodine cannot match. The stove fuel & snowmelt calculator builds a fuel budget from person-days, hot-water volume, wind and temperature factors plus the latent-heat penalty of melting snow, while the hydration & sweat planner sizes carry-water from a sweat-rate test instead of dangerous one-size-fits-all quotas.
First Aid & Health
Seven decision aids cover the injuries and illnesses that happen hours from help: a weight-aware first-aid kit builder, the hypothermia risk scorer cross-checked against the NWS wind-chill formula, the NOAA heat safety index, the official Lake Louise acute-mountain-sickness self-score in the altitude planner, a 110-compression CPR & bleeding metronome, a bite, sting and tick aid and a UV & sunscreen planner built from skin-typed burn times.
Wildlife Safety
The wildlife encounter assistant walks species-specific playbooks — black bears, grizzlies, cougars, moose and more — with the 100-yard / 91-meter minimum distance rules. The bear hang & food storage calculator solves PCT-method rope length and the 10-4-4 clearance geometry, the venomous snake lookup covers regional species by description alone, and the insect repellent planner times DEET, picaridin, permethrin-treated gear and sunscreen combinations.
Power & Electronics
The cold-weather power station converts mAh labels into real watt-hours and 5-volt output, derates lithium-ion capacity by temperature (including the never-charge-below-0°C rule), sizes solar panels against peak-sun hours and weather losses, and estimates headlamp runtime across high, medium, low and SOS strobe modes.
Weather & Navigation
Plan time with the Naismith hike-time planner, frostbite exposure with the NWS wind-chill calculator, storms with the flash-to-bang lightning timer and the 30/30 rule, immersion survival with the 1-10-1 cold-water planner, summit conditions with the lapse-rate mountain weather kit, your exact position with the WGS-84 coordinate converter (DD, DMS, UTM and MGRS), and rescue signalling with the timed light-and-sound SOS & Morse toolkit.
Trip & Gear
Close the planning loop with the Pandolf-equation calorie & food planner, the category-donut pack weight analyzer, seven-template smart trip checklist, pole/pad/bag gear fit advisor, ten-factor campsite evaluator and a printable emergency trip plan you leave with a contact. Every tool runs entirely in your browser, works offline once visited, and stores nothing on any server.
野外决策往往就是压力下的算术：几滴消毒剂、几分钟日照、多少克燃料、几米净空。本站把这些算术变成即时、有出处的答案——无论你正站在溪边、山口还是风雨欲来的山脊。
水与饮水
野外净水投药计算器 实现美国 CDC 与 EPA 的应急消毒指引：无香家用漂白剂（5.25–6% 与 8.25%）、2% 碘酊与二氧化氯，含浑水加倍、冷水接触时间惩罚，以及氯与碘无法覆盖的隐孢子虫 4 小时接触要求。炉具燃料与融雪计算器 按人·日数、热水量、风寒温度系数与融雪潜热惩罚计算燃料预算；饮水与出汗规划器 则基于出汗率测试而非危险的固定水量配额。
急救与健康
七个决策助手覆盖距救援数小时之外的伤病：按重量感知的急救包构建器、与 NWS 风寒公式交叉校验的失温风险评分器、NOAA 高温安全指数、采用官方 Lake Louise 急性高原病自评的高海拔规划器、每分钟 110 次的心肺复苏与止血节拍器、叮咬蜇伤蜱虫助手，以及按肤质灼伤时间构建的防晒 UV 规划器。
野生动物安全
野生动物遭遇助手 提供按物种区分的处置剧本——黑熊、灰熊、美洲狮、驼鹿等，含 100 码（91 米）最小距离规则。防熊悬挂与食物储存计算器求解 PCT 悬挂绳长与 10-4-4 净空几何；毒蛇查询仅凭文字特征覆盖各地区物种；驱虫剂规划器安排避蚊胺、派卡瑞丁、氯菊酯处理衣物与防晒霜的组合时效。
电力电子
低温电力站把 mAh 标签换算成真实瓦时与 5V 输出，按温度对锂电容量打折（含 0°C 以下禁充电规则），按有效日照与天气损耗估算太阳能板收益，并给出头灯高亮/中亮/低亮/SOS 频闪各档续航。
天气与导航求救
用 Naismith 徒步时间规划器安排时间，用 NWS 风寒冻伤计算器判断暴露时限，用声光闪电计时器执行 30/30 规则，用 1-10-1 冷水浸泡规划器判断存活窗口，用递减率山地天气套件预估山顶气温，用 WGS-84 坐标转换器（DD/DMS/UTM/MGRS）报出精确位置，用带声光时序的 SOS 摩斯码工具箱发出求救信号。
行程与装备
用 Pandolf 方程的热量与食物规划器、分类环形图的负重分析器、七套模板的智能出行清单、杖长/睡垫/睡袋装备适配顾问、十因素营地评估器，以及留给联系人的可打印紧急出行计划单完成规划闭环。所有工具完全在浏览器内运行，访问过即可离线使用，不在任何服务器上存储你的数据。
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