Calculators
Planning tools related to history & collected spaces, with visible assumptions and clearly explained results.
Estimate age at death from a person's birth and death dates by entering the elapsed years, months, and days. The result expresses the elapsed time as approximate years using a 365-day year and 30-day months.
Compare two ages entered as years, months, and days. This calculator uses a 30-day-month approximation to convert each age to total days before finding the absolute difference.
Estimate an art commission price from working time, hourly rate, materials, and a complexity factor. The result is a planning estimate based only on the values you provide.
Estimate paper cost for an art print run by multiplying the number of prints by the paper area used per print and the paper price per square inch. Enter all areas in square inches and prices in currency units per square inch.
Estimate the combined square-inch display area for a group of artifacts by multiplying the item count by the width and height of each artifact. Assumes every artifact has the same rectangular dimensions and excludes spacing, frames, mounts, and case clearance.
Estimate a bond's annual yield to maturity from its market price, face value, annual coupon, and years to maturity using an annual-payment assumption.
Compare an observed shared DNA amount with a reference centimorgan amount to calculate the percentage difference. This arithmetic comparison does not identify or predict a family relationship.
Estimate the resulting red, green, and blue channel values when mixing two colors by volume. This simplified model assumes each color contributes in proportion to its volume and does not model pigment chemistry or paint opacity.
Calculate the annualized growth rate between a starting value and an ending value over a number of years. Enter positive values and a duration from 0.1 to 100 years.
Estimate the fabric cost for a costume project from the number of garments, fabric yards needed per garment, and price per yard. The estimate assumes each garment uses the same amount of fabric and the same fabric price.
Calculate elapsed time between two recorded dates using a simple 365-day year and 30-day month convention. Enter the difference in years, months, and days to express the duration as total days.
Estimate price elasticity of demand with the midpoint method using a starting price, a positive price increase, starting quantity, and ending quantity. The result is signed and describes the percentage change in quantity relative to the percentage change in price.
Calculate what percentage of a DNA segment or set of segments represents of a chosen total DNA amount. Enter the measured DNA amount and the total amount using the same unit.
Calculate image print resolution in dots per inch from pixel dimensions and intended print size.
Convert a measured drawing length to its represented real-world length using a uniform scale ratio.
Estimate your effective tax rate by dividing total tax paid by taxable income. Enter amounts in the same currency and use a positive taxable income.
Convert an amount between currencies using an exchange rate you enter. The result is a simple estimate and does not include fees or live market data.
Estimate fabric yardage for rectangular panels by dividing the total cut area by usable fabric width, then adding a chosen allowance for seams, hems, pattern matching, and cutting waste. The estimate assumes each panel can be cut from the fabric width; check the layout for directional prints and large pieces.
Estimate the number of boxes needed to store family documents and photos using the capacity you expect each box to hold.
Estimate archive costs by multiplying the number of storage boxes by the cost per box and the number of pages by the cost per page, then adding both amounts. Enter your own rates; the estimate excludes costs not represented by these inputs.
Estimate the combined geometric volume of family archive boxes in cubic inches by multiplying the number of boxes by each box's length, width, and height. The estimate assumes every box has the same dimensions and does not account for gaps, shelving, packing materials, or irregular shapes.
Estimate the number of parent-to-child generation steps between two birth years using an average age at parenthood. This is a planning estimate for genealogy research, not proof of a family relationship.
Estimate the total time needed to interview relatives about family history, including planned breaks. Enter the number of relatives, interview minutes per person, and the number and length of breaks.
Estimate a research budget by adding archive visit costs and copy costs. Enter the number of visits, cost per visit, number of copies, and cost per copy in consistent currency units.
Estimate the number of photos that fit in your albums from the number of albums, pages per album, and photos per page.
Estimate a family reunion meal budget by multiplying the number of guests by meals per guest and the cost per meal. Enter your own planning figures; the estimate excludes any costs not included in the per-meal amount.
Estimate the perimeter of a rectangular picture frame from the artwork dimensions and an even mat border. The result is a planning measurement for the frame's four sides.
Calculate the GDP deflator from nominal GDP and real GDP measured in the same currency and period. The result is an index where 100 represents the chosen base-year price level.
Calculate GDP per capita by dividing a country's or region's gross domestic product by its population. Enter GDP and population in matching units to get GDP per person.
Calculate the approximate longer length in a golden-ratio proportion from a known shorter length. The result uses φ ≈ 1.6180339887 and is in the same unit as the input.
Estimate the printing budget for historical exhibit labels by multiplying the number of labels, cost per copy, and copies needed for each label.
Estimate the equivalent purchasing power of a historical U.S. dollar amount using a user-supplied average annual inflation rate and number of years. This is a simplified compound-growth estimate, not an official historical CPI lookup.
Find the proportional height or width of an image from its current dimensions and a target dimension. Enter the known width and height, then choose which dimension to resize while preserving the original aspect ratio.
Calculate the proportional height of an image when resizing it to a new width while preserving its original aspect ratio.
Estimate how a starting amount changes in purchasing-power terms over a chosen period using a user-supplied annual inflation rate and annual compounding assumption.
Estimate the horizontal length needed for an inscription from its character count, average space per character, line count, and line spacing. The estimate assumes uniform character spacing and measures total line lengths plus the spacing assigned to each line.
Estimate an exhibit's listed costs by adding display case costs, lighting, and labels. Enter whole-number counts and dollar amounts for a simple planning estimate.
Estimate the gross square footage of exhibit wall panels by multiplying the number of panels by the width and height of each panel. Assumes all panels have the same dimensions and counts their full rectangular face area.
Estimate a painting price from canvas area, your hourly labor rate and hours, material costs, and a complexity adjustment. The estimate combines these supplied amounts and does not set market rates.
Convert a paper measurement from millimeters, centimeters, or inches into another unit using the exact unit conversion factors shown in the formula.
Estimate the material cost of picture frame backing from the number of frames, backing dimensions, and price per square inch. The estimate assumes each frame uses one rectangular backing piece and excludes waste, labor, taxes, and other materials.
Calculate the outside dimensions of a picture mat from the artwork size and the border width on each side. This assumes equal borders and no extra overlap or frame allowance.
Convert a pixel measurement to centimeters using a selectable pixel density in pixels per inch (PPI).
Convert a pixel measurement to inches using the pixels-per-inch (PPI) value of the intended display or print output.
Calculate the physical print dimensions of an image from its pixel dimensions and the selected print resolution. The result is shown in inches.
Estimate how much a current amount of money would be worth in another year using the two years' price index values. This simple index-based estimate assumes both values use the same index series.
Estimate real GDP by adjusting nominal GDP for the GDP price index, where the index is expressed with the base year set to 100.
Calculate the width and height of each equal cell in a rule-of-thirds grid for a square canvas. Divide the canvas into three equal rows and three equal columns, with guide lines one cell-width from each edge.
Calculate the scale factor between an original measurement and its scaled measurement, then apply that factor to another measurement. Enter measurements in the same unit.
Calculate the unemployment rate from the number of unemployed people actively seeking work and the labor force total. Enter both counts in people.