Age Difference Calculator
Find the exact elapsed time between two birth dates, expressed as years, months, and days using a 365-day year and 30-day month convention.
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Calculators
Calculators
Planning tools related to local history & heritage, with visible assumptions and clearly explained results.
Archive Digitization Time Calculator
Estimate the hands-on digitization time for a batch of archive pages by multiplying the page count by the average minutes needed to digitize each page.
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Archive Exhibit Label Budget Calculator
Estimate the total printing budget for exhibit labels by multiplying the number of exhibits by labels per exhibit and cost per label. Enter counts in labels and costs in your chosen currency.
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Archive Exhibit Label Cost Calculator
Estimate the printing cost of archive exhibit labels by multiplying the number of labels by the cost per label. Enter a quantity and unit cost in the same currency. This estimate covers only the per-label cost you provide.
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Archive Photo Frame Cost Calculator
Estimate the cost of archive photo frames from the number of photos, frames per pack, and pack cost. The estimate assumes a proportional per-frame cost and does not account for partial-pack purchases or other expenses.
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Archive Research Budget Calculator
Estimate a straightforward archive research budget by adding hourly research costs to per-page copy costs. Enter your planned hours and pages, then supply the rates you expect to pay. This worksheet does not include travel, access, or other charges unless you include them in an input.
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Archive Shelf Length Calculator
Estimate the total linear shelf length needed for archive boxes by multiplying the number of boxes by the width of each box. This estimate assumes every box is stored side by side with its measured width facing the shelf length.
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Archive Supplies Cost Calculator
Estimate the total cost of archival boxes and labels using your quantities and per-item costs. This simple estimate covers only the supplies entered.
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Boat Fuel Range Calculator
Estimate a boat’s theoretical range in nautical miles from fuel onboard, fuel burn rate, and cruising speed. The estimate assumes steady conditions and does not include a reserve or changing conditions.
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Boat Passage Time Calculator
Estimate underway passage time by dividing a planned distance in nautical miles by average speed in knots. The result is in hours and does not account for stops, weather, currents, or route changes.
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Boat Propeller Slip Calculator
Estimate propeller slip as a percentage by comparing a boat’s measured speed with its theoretical speed based on engine RPM, gear ratio, and propeller pitch. The estimate assumes the supplied RPM is engine RPM, the gear ratio is engine-to-propeller reduction, pitch is in inches, and speed is in knots.
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Boat Speed Calculator
Estimate a boat's average speed from the distance traveled and elapsed time. Enter distance in nautical miles and time in hours to get speed in knots.
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Buoyant Force Calculator
Estimate the upward buoyant force on a fully submerged object from the surrounding fluid density, displaced volume, and gravitational acceleration. The result assumes static conditions and uniform fluid density.
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Cousin Relationship Calculator
Find the cousin degree and removal between two people from the number of generations each is below their nearest shared ancestor. This describes the standard genealogical relationship when that ancestor is correctly identified.
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Crop Factor Calculator
Calculate the equivalent focal length of a lens on a camera sensor using the lens focal length and crop factor.
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Equivalent Focal Length Calculator
Convert a lens's actual focal length to its 35mm-equivalent focal length using the camera sensor crop factor.
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Exposure Compensation Calculator
Calculate the adjusted exposure value in stops by applying exposure compensation to a camera meter's recommended exposure value.
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Exposure Value Calculator at ISO 100
Estimate exposure value (EV) at ISO 100 by adding the stop values for an idealized full-stop aperture and shutter speed.
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Family Archive Digitization Time Calculator
Estimate the hands-on time needed to digitize a family archive by multiplying the number of photos and document pages by the time spent on each item, then adding both totals.
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Family Archive Scanning Cost Calculator
Estimate the scanning charge for a family archive by multiplying the number of pages by the price per page. This estimate covers only the per-page scanning charge you enter and does not include other services or fees.
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Family Archive Storage Box Volume Calculator
Estimate the combined volume occupied by family archive boxes using their exterior length, width, height, and the number of boxes. The result is expressed in cubic inches.
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Family Document Inventory Calculator
Estimate the total number of family documents represented by your boxes using an average documents-per-box count.
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Family Tree Ancestor Slots Calculator
Estimate the number of ancestor slots represented across a chosen number of generations, assuming each person has two parent slots per generation. The estimate counts positions in a theoretical tree and does not account for duplicate ancestors or missing records.
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Field of View Calculator
Estimate the horizontal scene width covered by a rectilinear lens at a given distance using sensor width and focal length. The result is a linear field width in the same units as distance.
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Flash Guide Number Calculator
Estimate flash guide number or the maximum flash-to-subject distance from guide number, aperture, and ISO. The calculation assumes the guide number is specified at ISO 100 and adjusts it for the selected ISO.
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Focal Length Calculator
Calculate a lens focal length from image distance and magnification using a thin-lens model. Enter both distances in the same unit.
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Genealogy Archive Box Count Calculator
Estimate the number of archive boxes needed by dividing the number of documents by the number of documents each box holds. The result may be fractional because this calculator reports the arithmetic estimate, not a rounded-up packing count.
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Historic Book Value Calculator
Estimate a historic book's future value by applying a user-entered annual percentage change over a chosen number of years. This simple compound-growth model does not appraise a book or account for condition, rarity, inflation, or market evidence.
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Historical Map Storage Area Calculator
Estimate the total flat storage area for a collection of historical maps using the number of maps and each map’s length and width in centimeters. This simple estimate assumes every map has the same dimensions and is stored flat without accounting for folders, sleeves, spacing, or container thickness.
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Hull Speed Calculator
Estimate a displacement boat’s theoretical hull speed in knots from its waterline length, using the traditional square-root rule. This is a reference estimate, not a prediction of actual speed.
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Hyperfocal Distance Calculator
Estimate hyperfocal distance and near depth-of-field limit from focal length, aperture, and circle of confusion, using the standard thin-lens approximation.
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Image Aspect Ratio Calculator
Calculate an image's aspect ratio from its pixel width and height, and see the width-to-height ratio in simplified form.
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Image Aspect Ratio Resizer
Calculate the new height for an image when resizing it to a target width while preserving its original aspect ratio.
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Knots to Miles per Hour Converter
Convert a speed in knots to its equivalent in miles per hour using the standard nautical mile conversion factor.
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Macro Magnification Calculator
Calculate approximate image magnification by dividing the image size recorded on the sensor by the subject's actual size. Enter both measurements in the same units.
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Nautical Miles to Kilometers Converter
Convert a distance in nautical miles to kilometers using the standard international nautical mile conversion factor.
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Nautical Miles to Miles Converter
Convert a distance in nautical miles to statute miles using the standard conversion factor of 1 nautical mile = 1.15078 miles.
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Pedigree Collapse Calculator
Compare the theoretical number of ancestor slots across selected generations with the number of distinct ancestors you estimate. The difference is a simplified measure of pedigree collapse.
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Photo Album Storage Volume Calculator
Estimate the combined physical volume of your photo albums in cubic centimeters from their count and dimensions. This is a simple rectangular-volume estimate and does not include shelves, packing material, or extra clearance.
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Photo Enlargement Resolution Calculator
Estimate the average pixel density of a print from a source image's pixel dimensions and the desired print dimensions in inches. The result is a simple planning measure and does not assess image quality or guarantee print sharpness.
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Photo Exposure Reciprocity Calculator
Estimate the shutter time needed to maintain the same exposure when changing aperture. This calculation assumes unchanged scene brightness and ISO, and does not compensate for film reciprocity failure.
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Photo Print Size Calculator
Estimate a photo's print dimensions from its pixel dimensions and a chosen print resolution. Enter the image width and height in pixels and the target resolution in pixels per inch (PPI).
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Photo Storage Calculator
Estimate the storage space needed for a photo collection from its photo count and average file size. Choose the file-size unit and output unit to see an approximate total capacity requirement.
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Pixel Density Calculator
Estimate a display's pixel density in pixels per inch (PPI) from its pixel resolution and diagonal screen size.
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Pixels to Inches Converter
Convert a digital image's pixel dimensions to print dimensions in inches using the resolution in pixels per inch (PPI).
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Rhode Island Monthly Cost of Living Calculator
Estimate a household's monthly living costs in Rhode Island by adding housing, utilities, groceries, transportation, and other expenses. Enter your own amounts; this is a budgeting worksheet, not an official cost index or forecast.
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Rhode Island Sales Tax Calculator
Estimate Rhode Island sales tax and a purchase total from a taxable purchase amount and a user-entered tax rate. This is a simple arithmetic estimate and does not determine whether an item is taxable or which rate legally applies.
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Rhode Island Trip Cost Calculator
Estimate a Rhode Island trip budget by combining lodging, meals, local transportation, activities, and other planned expenses for your group and trip length.
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Timelapse Interval and Clip Length Calculator
Estimate the number of frames captured and the finished timelapse clip length from your capture duration, frame interval, and playback frame rate.
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Wave Speed Calculator
Calculate wave speed by multiplying frequency in hertz by wavelength in meters. Enter values measured for the same wave and receive speed in meters per second.
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