Free Online Calculators
Finance, math, health, construction, and everyday tools in one searchable catalog.
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Cross Stitch Fabric Calculator — Size, Fit & Start Position
Depth of Field Calculator — Focus & Scene Planner
Diagonal Quilt Backing Calculator
Drip Irrigation Calculator — Flow & Timer Comparison
Fabric Yardage & Cut Layout Calculator
Free Date Calculator — Days Between Dates & Age Calculator
Generator Sizing Calculator — Running & Starting Watts
Granny Square Blanket Calculator
Headphone Power Calculator
IPv4 Subnet Calculator
Knitting Increase & Decrease Calculator
LED Resistor Calculator
Calculator descriptions
Cross Stitch Fabric Calculator — Size, Fit & Start Position
Size fabric for your cross stitch chart, compare counts, check an existing piece and see exactly where the design starts.
Depth of Field Calculator — Focus & Scene Planner
Check depth of field for your camera settings or choose a balanced focus distance and aperture to cover the near and far subjects in your scene.
Diagonal Quilt Backing Calculator
Plan a diagonal quilt backing with a rounded cut length, illustrated slide and seam, straight-panel comparison and printable cutting plan.
Drip Irrigation Calculator — Flow & Timer Comparison
Compare water delivered to different plant groups on one timer. Use rated emitter flow or a measured catch test, and see which groups receive more or less than their entered target.
Fabric Yardage & Cut Layout Calculator
Lay out rectangular fabric pieces with grain controls. Calculate yardage to buy, check an existing cut and print your cutting worksheet.
Free Date Calculator — Days Between Dates & Age Calculator
Calculate days between dates, add or subtract days, or find an exact age with weekend controls, clear steps, and instant visual results.
Generator Sizing Calculator — Running & Starting Watts
Size a generator from your appliance nameplate watts. Compare steady load, controlled motor starts and overlapping starts against both generator ratings.
Granny Square Blanket Calculator
Plan a blanket from measured motifs, edit its assembly map and calculate colour-specific yarn and whole balls after partial stock.
Headphone Power Calculator
Convert headphone sensitivity into required voltage, current and power. Compare headphones and explicit amplifier voltage and current limits.
IPv4 Subnet Calculator
Inspect IPv4 networks and plan aligned, nonoverlapping subnets for different host requirements. See exact address counts, /31 links, /32 routes and remaining CIDR blocks.
Knitting Increase & Decrease Calculator
Plan evenly spaced M1, KFB or K2tog in one knit row or round. Follow exact source stitches, step through the row and print your instructions.
LED Resistor Calculator
Choose a standard resistor for small DC LEDs, check a resistor you have and see current, power and wiring for series strings or parallel branches.
