Calculators
Decision-support tools for sizing, cost, capacity, runtime, ownership, and other practical planning questions.
Estimate air pressure at an elevation using a simplified standard-atmosphere model. Enter the starting pressure and elevation, then choose metric or imperial units. The model assumes standard sea-level temperature and conditions, so actual weather pressure can differ.
Estimate air temperature at a higher or lower elevation from a known temperature and elevation using a fixed average lapse rate. This is a planning estimate, not a local forecast.
Estimate an appliance's running power use in watts from its voltage and current, or convert a labeled kilowatt rating to watts. This is a nameplate estimate and does not account for startup surges or changing loads.
Estimate the total food weight to pack for a backpacking trip from trip length, planned food weight per person per day, and group size. The estimate assumes each person eats the same amount each day and does not account for packaging or food left over.
Estimate a trip's total stove fuel cost from the number of days, fuel used per day, and cost per fuel unit. The estimate assumes daily use stays constant and excludes other trip expenses.
Estimate your loaded backpack weight by adding your base gear, food, water, and fuel. Enter each amount in pounds to see the total carried weight.
Estimate ideal battery charging time from battery capacity, starting charge, target charge, and charger current. The estimate assumes constant current and does not account for charging losses or tapering.
Convert a Canadian dollar amount to US dollars using an exchange rate you provide. The estimate does not include fees or rate changes.
Estimate the fuel cost for a camping trip from your daily fuel use, trip length, and fuel price per kilogram. The estimate assumes a steady daily use rate and does not include a reserve or other trip costs.
Estimate the total water volume to pack for a camping trip from the group size, days, daily water allowance per person, and a reserve percentage. This planning estimate does not account for changing conditions or guarantee that a supply is safe to drink.
Convert one latitude or longitude angle from degrees, minutes, and seconds (DMS) to decimal degrees using its hemisphere. This tool converts a single angle only and does not convert datums or map projections.
Calculate the time between a supplied sunrise and sunset for outdoor planning. Enter both times in 24-hour clock hours and minutes.
Estimate dew point from air temperature and relative humidity using Mark Lawrence’s approximate moist-air rule of thumb.
Estimate basic driving time from a planned distance and an assumed average speed. The result is distance divided by speed and does not account for stops or changing road conditions.
Estimate the total calories and approximate food weight to plan for an emergency supply based on household size, duration, and a calorie-per-person daily planning assumption. This worksheet does not determine individual nutritional needs or guarantee a balanced menu.
Estimate an emergency savings target by multiplying monthly essential expenses by the number of months you want to cover.
Estimate the combined volume of emergency kit items by multiplying the number of items by their average volume. The estimate assumes every item has the same volume and does not account for packaging, empty space, or how items fit together.
Estimate voltage drop and load-end voltage for a single-phase, two-conductor copper extension cord using cord length, wire resistance, supply voltage, and load current. The model assumes steady current and does not account for temperature, connections, or other circuit conditions.
Estimate the total ferry fare for a trip by combining passenger fares and vehicle fares. Enter the number of passengers and vehicles, then the fare for each. The estimate uses only the fares you provide and does not include other trip costs.
Estimate the firewood volume needed for a planned period using daily consumption, burn days, and a reserve allowance. This is a planning estimate based on the quantities you enter.
Estimate flight duration in hours from route distance and average ground speed. This is a simple arithmetic estimate, not a scheduled flight time, and it excludes route details, winds, delays, and time zones.
Estimate the fuel cost of a trip from its distance, your vehicle’s fuel economy, and the price of fuel. The estimate assumes fuel economy and fuel price stay constant for the distance entered.
Calculate fuel economy in miles per gallon from the distance traveled and fuel used. Enter trip miles and gallons consumed to estimate a trip's gas mileage.
Estimate a planning capacity for emergency backup by adding essential equipment running watts, the largest startup surge, and a reserve margin. This worksheet assumes one selected motor load starts at a time and does not replace equipment manuals or a qualified electrical assessment.
Estimate a route's horizontal distance from its north-south and east-west coordinate changes, using a user-supplied local distance per degree. This flat-plane approximation does not calculate a precise geodesic or follow terrain.
Estimate the heat index in degrees Fahrenheit from air temperature and relative humidity using the National Weather Service Rothfusz regression. The estimate applies to warm conditions and does not account for direct sun, wind, clothing, activity, or individual health factors.
Estimate calories burned on a hike from body weight, hiking time, distance, and elevation gain using a transparent pace-and-climbing worksheet model. This is a planning estimate, not a measurement of individual energy use.
Estimate cumulative elevation gain from the uphill segments in a planned hike profile. Enter each segment's elevation change in feet or meters, using positive values for climbs and negative values for descents.
Estimate your average hiking pace in minutes per mile from planned distance and moving time. This simple estimate assumes a steady pace and does not adjust for elevation, terrain, breaks, or weather.
Estimate hiking time from route distance, elevation gain, your moving pace, and a terrain adjustment. The result is a moving-time estimate and excludes breaks, navigation delays, and changing trail conditions.
Convert a measured distance on a map into its real-world distance using the map scale ratio.
Convert a distance in miles to kilometers using the standard factor of 1.609344 kilometers per mile.
Estimate walking time from route distance and total ascent using the traditional Naismith Rule assumption of 1 hour per 5 km plus 1 hour per 600 m of ascent.
Estimate moving time for a hiking route from distance, elevation gain, and elevation loss. The estimate uses a stated pace and elevation adjustment, so it is a planning aid rather than a route-specific forecast.
Estimate the combined cubic-meter volume of items you are planning to transport by ferry. Enter the item count and the volume of one item to calculate their total cargo volume.
Convert a running or hiking pace into speed per hour. Enter minutes and seconds per mile or kilometer, then choose the distance unit.
Estimate the combined nominal stored energy of a set of portable batteries by multiplying the number of batteries by the capacity of each battery in watt-hours. The result is a nameplate energy total and does not estimate usable energy or runtime.
Estimate how long a portable power station can run a device or combined load using battery capacity, usable capacity, inverter efficiency, and the load's average watt draw. The estimate assumes a steady load and does not account for changing conditions or manufacturer-specific cutoffs.
Estimate the rainwater volume a roof can collect from its area, rainfall depth, and collection efficiency. This is a planning estimate and does not account for storage limits, water quality, or local requirements.
Estimate the total fuel, lodging, food, and activity costs for a road trip using your trip distance, vehicle efficiency, fuel price, nights away, and daily spending estimates.
Estimate the solar panel array wattage needed to supply a stated amount of daily energy, based on peak sun hours and an assumed system efficiency.
Estimate the electricity cost of running a space heater from its wattage, daily use, number of days, and electricity price.
Estimate toll charges for a planned drive from the route distance, the share of the route subject to tolls, an average toll cost per distance unit, and whether you are traveling one way or returning along the same route. This is a planning estimate, not a route-specific quote.
Estimate the total cost of laundry during a trip by multiplying the number of loads by the cost per load. Enter costs in your chosen currency.
Estimate driving time from distance and average speed. This calculation assumes a steady average speed and does not include stops or changing road conditions.
Estimate a trip budget from traveler count, nights, transport per person, lodging per night, and daily spending per person. This simple worksheet assumes the same lodging and daily spending rates throughout the trip.
Estimate fees for exchanging travel money by applying a percentage fee to the amount exchanged and adding any fixed fee. Enter all currency amounts in the same units. This estimate does not convert currencies or account for exchange-rate differences.
Estimate planned trip time in hours by combining the number of travel days, planned hours per day, and any additional hours. This simple planning estimate does not account for schedules, delays, or time-zone changes.
Estimate a household's emergency water storage volume from the number of people and planned days of self-sufficiency. This basic planning estimate uses a user-selected daily allowance per person and does not account for pets, sanitation, heat, illness, or other special needs.
Estimate wind chill in degrees Fahrenheit using air temperature in Fahrenheit and wind speed in miles per hour. Uses the National Weather Service formula for temperatures at or below 50°F and wind speeds above 3 mph.