Interactive calculations need JavaScript. You can browse tool pages below and read their formulas.
WaterEstimate a chosen water reserve with a contingency allowance.
Works offline · No account needed
WaterEstimate runoff collected from a roof or other collection surface.
Works offline · No account needed
WaterEstimate the internal volume of an upright cylindrical container.
Works offline · No account needed
WaterCompare usable inventory with a chosen daily consumption rate.
Works offline · No account needed
WaterPlan whole delivery trips for a water volume, allowing for transfer loss.
Works offline · No account needed
WaterEstimate filling time at several equally supplied taps.
Works offline · No account needed
WaterInclude containers when estimating the mass of a shared water carry.
Works offline · No account needed
WaterBuild a daily water budget from separate uses.
Works offline · No account needed
WaterCompare opening stock and expected collection with planned daily use.
Works offline · No account needed
WaterEstimate how often a shared distribution container needs replenishment.
Works offline · No account needed
Food & provisionsEstimate the energy represented by one inventory and its planning duration.
Works offline · No account needed
Food & provisionsConvert a planned ingredient amount into whole packages to obtain.
Works offline · No account needed
Food & provisionsScale one ingredient for a new number of servings.
Works offline · No account needed
Food & provisionsForecast a staple inventory using household consumption records.
Works offline · No account needed
Food & provisionsEstimate the pace needed to use a batch within a chosen rotation period.
Works offline · No account needed
Food & provisionsPlan volunteer time from a measured preparation rate.
Works offline · No account needed
Food & provisionsEstimate ingredient expenditure and a contingency amount.
Works offline · No account needed
Food & provisionsEstimate stock using each animal’s established feeding amount.
Works offline · No account needed
Food & provisionsEstimate shelf length for rectangular food packages.
Works offline · No account needed
Food & provisionsAccount for a measured trimming or handling loss in ingredient purchases.
Works offline · No account needed
Growing & soilCount planting positions on a regular grid inside a garden bed.
Works offline · No account needed
Growing & soilAllow for germination and survival losses when planning seed starts.
Works offline · No account needed
Growing & soilEstimate growing medium for several rectangular beds.
Works offline · No account needed
Growing & soilCompare a crop yield scenario with household demand.
Works offline · No account needed
Growing & soilPlan repeated sowing batches over a selected window.
Works offline · No account needed
Growing & soilTranslate a chosen irrigation depth into delivered water volume.
Works offline · No account needed
Growing & soilEstimate mulch quantity after excluding areas you will leave uncovered.
Works offline · No account needed
Growing & soilCompare a planned holding period with bin volume.
Works offline · No account needed
Growing & soilEstimate the labor needed to harvest an expected crop amount.
Works offline · No account needed
Growing & soilApply an observed germination test to a seed inventory.
Works offline · No account needed
EnergyEstimate runtime from stored energy and a constant appliance load.
Works offline · No account needed
EnergyEstimate daily energy from a rated array and equivalent full-sun hours.
Works offline · No account needed
EnergyInclude operating and standby periods in a device energy estimate.
Works offline · No account needed
EnergyEstimate a lower-bound recharge time from available charging power.
Works offline · No account needed
EnergyUse measured fuel consumption to estimate operating time.
Works offline · No account needed
EnergyEstimate full device charges from a power bank’s watt-hour rating.
Works offline · No account needed
EnergyEstimate energy for an appliance that cycles on and off.
Works offline · No account needed
EnergyPlan batches of charging sessions and their energy demand.
Works offline · No account needed
EnergyEstimate lighting energy across fixed and portable lights.
Works offline · No account needed
EnergyCompare a usable energy reserve with daily demand after expected generation.
Works offline · No account needed
Shelter & homeEstimate a planning footprint for personal spaces and shared circulation.
Works offline · No account needed
Shelter & homeMatch complete kits to households, including a chosen spare allowance.
Works offline · No account needed
Shelter & homeEstimate covered area when rectangular sheets overlap in a grid.
Works offline · No account needed
Shelter & homeEstimate vehicle space for packed kits with loading inefficiency.
Works offline · No account needed
Shelter & homeEstimate bedding sets needed while used sets are unavailable for cleaning.
Works offline · No account needed
Shelter & homeEstimate routine cleanup time for a measured floor area.
Works offline · No account needed
Shelter & homeUse consumption and delivery delay to set a chosen stock trigger.
Works offline · No account needed
Health & wellbeingPlan vehicle journeys for scheduled care appointments.
Works offline · No account needed
Health & wellbeingEstimate person-hours for a chosen nonclinical support roster.
Works offline · No account needed
Health & wellbeingEstimate inventory duration for one ordinary personal care consumable.
Works offline · No account needed
Health & wellbeingEstimate travel time using a person’s measured comfortable pace and planned stops.
Works offline · No account needed
Health & wellbeingEstimate volunteer time for consent-based social check-ins.
Works offline · No account needed
Sanitation & hygieneEstimate water inventory from a locally chosen use pattern.
Works offline · No account needed
Sanitation & hygieneEstimate refill frequency from a measured dispenser output.
Works offline · No account needed
Sanitation & hygieneEstimate package quantities using observed paper consumption.
Works offline · No account needed
Sanitation & hygieneEstimate storage for ordinary solid waste between collections.
Works offline · No account needed
Sanitation & hygieneEstimate loads and water from a measured machine program.
Works offline · No account needed
Sanitation & hygieneCompare tableware demand with measured washing throughput.
Works offline · No account needed
Sanitation & hygieneEstimate collection capacity pending approved wastewater handling.
Works offline · No account needed
CommunityEstimate staffing for daily service coverage with breaks and reserve cover.
Works offline · No account needed
CommunityAllow time for everyone to speak in structured discussion rounds.
Works offline · No account needed
CommunityEstimate how many sessions fit in a facility’s daily schedule.
Works offline · No account needed
CommunityForecast an assistance queue using observed arrivals and completions.
Works offline · No account needed
CommunityEstimate the number of rounds in an ideal expanding contact tree.
Works offline · No account needed
CommunitySummarize contributions and assistance received in a time exchange.
Works offline · No account needed
CommunityCompare a transparent per-person allocation across two groups.
Works offline · No account needed
CommunityMeasure participation and the next outreach workload.
Works offline · No account needed
CommunicationPlan airtime for an established, authorized group check-in.
Works offline · No account needed
CommunicationEstimate end-to-end delay in a sequential store-and-forward chain.
Works offline · No account needed
CommunicationEstimate storage for locally retained text messages.
Works offline · No account needed
CommunicationPlan paper sheets and print impressions for a multilingual notice.
Works offline · No account needed
CommunicationExplore expected contact success over several independent attempts.
Works offline · No account needed
Knowledge preservationCombine documents, images, audio and video into a storage estimate.
Works offline · No account needed
Knowledge preservationEstimate bulk copying or downloading time from a measured link rate.
Works offline · No account needed
Knowledge preservationEstimate the time for a full read and per-file verification work.
Works offline · No account needed
Knowledge preservationCompare total storage required for independent full copies with available media.
Works offline · No account needed
Knowledge preservationInclude preparation and review in a document scanning estimate.
Works offline · No account needed
Knowledge preservationEstimate raster size before compression for a scanning scenario.
Works offline · No account needed
Knowledge preservationPlan a rolling replacement cycle for storage media.
Works offline · No account needed
Knowledge preservationEstimate labor to describe, classify and review a collection.
Works offline · No account needed
Repair & makingCompare direct spending and an optional value assigned to your time.
Works offline · No account needed
Repair & makingEstimate the better of two uniform cutting orientations.
Works offline · No account needed
Repair & makingTranslate a manufacturer-based operating-hour interval into a planning date offset.
Works offline · No account needed
Repair & makingEstimate a pool of interchangeable spare parts under a simple event-rate scenario.
Works offline · No account needed
Repair & makingEstimate sequential identification, inspection and cataloging effort for a material lot.
Works offline · No account needed
PreparednessAdd the main categories of a personal kit and compare with a chosen planning limit.
Works offline · No account needed
PreparednessEstimate route consumption and usable range from recorded fuel economy.
Works offline · No account needed
PreparednessCompare a planned journey with locally verified remaining daylight.
Works offline · No account needed
PreparednessCompare a scenario’s relative priority using an explicitly subjective score.
Works offline · No account needed
PreparednessEstimate a working schedule after allowing for nonproductive time.
Works offline · No account needed
PreparednessCompare separately calculated supply durations to find the earliest constraint.
Works offline · No account needed
PreparednessBudget time for recurring household or community reviews.
Works offline · No account needed
PreparednessEstimate a random sample size to have a chosen chance of finding at least one error.
Works offline · No account needed
Land & ecosystemsConvert measured route segments on a paper map to ground distance.
Works offline · No account needed
Land & ecosystemsConvert elevation change and horizontal distance into a geometric gradient.
Works offline · No account needed
Land & ecosystemsPlan observation effort for evenly spaced walking lines in a rectangular study area.
Works offline · No account needed
Learning & cultureEstimate completion time for reading paired with deliberate practice.
Works offline · No account needed
Learning & cultureExplore a chosen sequence of increasingly spaced review sessions.
Works offline · No account needed
Learning & cultureExplore the reach of repeated peer teaching under explicit assumptions.
Works offline · No account needed
Learning & culturePlan group size and elapsed time for rotating practice stations.
Works offline · No account needed