Vertical Safe Zone Calculator
Turn top/bottom/side margin percentages into pixel insets for 9:16 vertical video (Shorts, Reels, etc.). Planning helper—not official platform specs.
計算機を使う
Knitting Gauge Calculator
Convert stitches and rows per 10 cm ↔ per inch for pattern scaling.
計算機を使う
Crochet Hook Size Calculator
Match hook diameter in mm to common US letter / number labels (approximate chart).
計算機を使う
DPI Print Width Calculator
Pixels and DPI to print width in inches; handy for photo prints.
計算機を使う
Aspect Ratio Calculator
Given width and ratio W:H, compute height (or scale both sides by a factor).
計算機を使う
Video File Size Calculator
Bitrate and duration to estimated file size (Mbps, minutes).
計算機を使う
Bandwidth Download Time Calculator
File size and download speed to approximate transfer time.
計算機を使う
Voltage Divider
Vin, R1, R2—no-load output at the divider tap.
計算機を使う
Parallel Resistance
Two resistors in parallel—equivalent Ω.
計算機を使う
Ohm's Law
Solve for V, I, or R from the other two values.
計算機を使う
LED Series Resistor
Vs, Vf, target mA—ballast R and resistor power.
計算機を使う
Bytes → KiB / MiB / GiB
Byte count using binary 1024 prefixes.
計算機を使う
RPM Surface Speed
RPM and diameter in inches—rim speed ft/min and m/s.
計算機を使う
Luggage Linear cm
Sum of three bag dimensions vs airline linear limit.
計算機を使う
BPM → Quarter ms
Tempo to quarter-note length for delay/MIDI math.
計算機を使う
Architectural Scale
mm on plan at 1:N scale to real meters.
計算機を使う
Duplex Print Sheets
Page count double-sided—physical sheets needed.
計算機を使う
Video Frame Count
FPS and duration in seconds—total frames.
計算機を使う
Video Letterbox Fit
Display px and video aspect—inner size and bars.
計算機を使う
Words → Pages
Word count and words per page—pages to print.
計算機を使う
Knit Stitches Width
Gauge per 10 cm and width—stitches to cast on.
計算機を使う
IPv4 Subnet
Address and CIDR—mask, network, broadcast, host range, counts.
計算機を使う
Screen PPI
Diagonal inches and pixel width/height—pixels per inch.
計算機を使う
WCAG Contrast
Two hex colors—contrast ratio and quick AA hint.
計算機を使う
URL Encode / Decode
Percent-encode or decode text for query strings.
計算機を使う
HTML Escape
Escape < > & quotes for safe HTML snippets.
計算機を使う
PCM Audio Size
Sample rate, bit depth, channels, seconds—uncompressed bytes.
計算機を使う
Text → Base64
UTF-8 to Base64 and character counts—runs locally.
計算機を使う
dBm → mW
RF power conversion.
計算機を使う