Daylight Length Calculator - Online Sunrise Sunset Duration
For any latitude and date, calculate the exact daylight hours. See golden hour. Useful for gardening and travel.
UD5 Toolkit
Find precise sunrise, sunset, twilight, and golden hour for any location on Earth.
For any latitude and date, calculate the exact daylight hours. See golden hour. Useful for gardening and travel.
Calculate antenna element lengths for a given frequency (or vice versa). Supports 1/4 wave, 1/2 wave, dipole. Useful for ham radio. Local only.
Enumerate all fonts installed on your device and see a real‑time preview. Useful for design tools. Permission required.
Select a local font and see all its metrics: ascent, descent, x‑height, and supported features. Typography deep dive.
Enter target total weight and bar weight to see which plates to put on each side. No more counting errors.
Search by country or currency name to find its symbol and code. Quick static reference for international business.
Load a WAV file and see its real-time oscilloscope trace and frequency spectrum. Zoom and pan. Pure frontend.
Use the document.fonts API to check if a font is loaded. Watch the ready promise. Avoid FOUT. JavaScript demo.
Paste a Base64 encoded font string and generate the complete @font‑face CSS rule. Inline small fonts easily.
Paste two strings that look the same and see if they differ after normalization. Debug invisible encoding bugs.
Enter two city names or coordinates and get the straight‑line distance in miles/km. Local calculation.
Calculate ideal stereo speaker placement (toe-in, distance from wall) for best soundstage. Visual diagram. For audiophiles. Local tool.
Find the optimal TV size for your room or the best viewing distance based on screen size and resolution (1080p, 4K, 8K). Simple THX/SMPTE reference.
Estimate BAC based on gender, weight, drinks consumed, and time. Uses Widmark formula. Educational tool, never encourage drunk driving. Local only.
Find out what day number of the year any date is (1‑366). Also shows days remaining. Simple reference.
Calculate the age of the moon in days since the last new moon. See illumination percentage. Simple algorithm.
Calculate the exact number of days, weeks, months, and workdays between two dates. Visual calendar highlights. Perfect for projects.
Combine multiple identical batteries in series and parallel and see the resulting voltage and total capacity. Electronics helper.
Track your subscriptions, calculate monthly and yearly totals, and find savings by pausing unused services. Local data.
Determine the minimum sample size needed for a survey or A/B test with a given confidence level and margin of error.
Compute confidence intervals for a population mean (known/unknown sigma) and proportion. All popular Z/T values. Local.
Easily compute posterior probabilities given prior, likelihood, and marginal likelihood. Visual diagram. All local.
Enter a number to find its golden ratio long and short segments. Use for pleasing design layouts. Instant.
Find out how large you can print based on image resolution in pixels. Understand DPI and megapixels.
Learn about f‑stops and their effect on light and depth. Calculate equivalent exposure adjustments. Educational.
Find the CAGR of an investment given start and end values over a time period. Instant growth rate.
Measure your waist‑to‑hip ratio and learn about associated health risks. WHR interpretation. Educational only.
Find what day of the week any past or future date falls on. Uses Zeller’s congruence. Fun historical reference tool.
Enter two sides of a right triangle and get the third. Also gives area and perimeter. Simple and visual.
Find the centroid (center of mass) of any convex polygon by entering vertex coordinates. Useful for physics and design.