Free Online Calculators & Tools
Aspect ratio, DPI, megapixel, color, MBTI, eGFR β 20+ free calculators and converters. No signup required.
π°π· νκ΅μ΄ νμΌλ‘Aspect Ratio Calculator (16:9, 4:3)
Calculate 16:9, 4:3, 21:9, 1:1, 9:16 pixel sizes. Resize screens, photos, videos.
DPI / PPI Calculator
Pixels per inch, print size at 72, 150, 300, 600 DPI. Pixels β inches converter.
Megapixel Calculator
Pixels β megapixels. 1080p, 4K, 12MP, 24MP resolution lookup.
Screen PPI Calculator
Calculate monitor / phone pixel density from diagonal size and resolution.
Image Size Calculator
Estimate uncompressed JPG / PNG file size from pixel resolution.
Image File Size (Target KB/MB)
Find the resolution that fits under a target file size (KB or MB).
Color Code Converter
Convert between HEX, RGB, and HSL.
HEX to RGB
Convert HEX color codes to RGB instantly.
RGB to HEX
Convert RGB values to HEX codes.
Color Palette Generator
Complementary, analogous, and triadic palettes.
Base64 Encoder/Decoder
Encode text to Base64 or decode Base64 strings.
URL Encoder/Decoder
Encode or decode URL-encoded strings.
JSON Formatter
Beautify or minify JSON data.
JWT Decoder
Decode JWT tokens to inspect Header and Payload.
UUID Generator
Generate UUID v4 identifiers quickly.
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-512 hashes.
QR Code Generator
Create QR codes from text or URLs.
Barcode Generator
Generate Code128 barcodes.
MBTI Personality Test
Age-appropriate test for kids, teens, and adults.
Blood Type Personality & Compatibility
Traits and love compatibility chart for A, B, O, AB.