Guides JP

Scientific Notation Converter Tool

Convert between decimal numbers and scientific (E) notation. Supports a×10ⁿ form, E notation, engineering notation, and significant figures.

Last updated: 2026/10/16 Developer Feedback & bug reports
Options
Enter a number
Scientific notation a×10ⁿ
—
E notation E
—
Engineering notation ENG
—
Decimal notation DEC
—
About the notations
a×10ⁿa×10ⁿ form (1≤|a|<10). The standard scientific notation in math and science
EE notation used in calculators and code. 1.5e3 = 1.5×10³
ENGExponent aligned to multiples of three, matching units like k (10³) and M (10⁶)
DECThe plain decimal number with the point written out

How to Use

1

Enter a number

You can type a plain decimal (12345.678) or E notation (1.5e3) — either works.

2

Auto convert

As you type, the number is converted to scientific, E, engineering, and decimal forms.

3

Adjust options

Set the number of significant figures or toggle the engineering notation display.

4

Copy the result

Use the copy button next to each notation to copy the format you need in one click.

About This Tool

A free online tool to convert between decimal numbers and scientific (E) notation. It supports a×10ⁿ form, E notation used in calculators and code (1.5e3), and engineering notation that aligns the exponent to multiples of three. The input is processed as a string, minimizing floating-point rounding errors for accurate conversion.

Features

  • Four notations at onceConvert and display scientific, E, engineering, and decimal notation simultaneously.
  • Error-aware conversionNumbers are processed as strings to minimize floating-point rounding errors.
  • Significant figures & engineeringSet significant figures or align the exponent to multiples of three.
  • Privacy protectedAll processing happens in your browser. Your input is never sent to a server.

Use Cases

  • Format physics and chemistry results in scientific notation
  • Turn calculator or program E notation (1.5e3) back into a plain number
  • Match engineering units like k, M, G in groups of three digits
  • Report consistent significant figures in papers and reports
  • Inspect scientific-notation values found in CSV files or logs

FAQ

What is E notation?
E notation (scientific notation) expresses large or small numbers as a mantissa times a power of ten. In calculators and code it is written like "1.5e3", which means 1.5×10³ = 1500. The number after the "e" is the power of ten.
What is engineering notation?
Engineering notation aligns the exponent to multiples of three (…, 10⁻³, 10⁰, 10³, 10⁶, …). It maps directly to SI prefixes such as k (kilo = 10³), M (mega = 10⁶), and m (milli = 10⁻³), so it is common in electrical and mechanical engineering.
What does setting significant figures do?
It rounds the result to the chosen number of significant digits. For example, 12345 at 3 significant figures becomes 1.23×10⁴. Choosing "Auto" shows the entered number without rounding.
Are there floating-point errors?
No. This tool does not convert your input into a numeric type; it processes the digits as a string. This avoids common floating-point rounding issues (such as 0.1 + 0.2) and preserves the exact digits you entered while switching notations.
Is my number sent to a server?
No. All conversion runs entirely in your browser with JavaScript. Your input is never transmitted to or stored on any external server, so you can use the tool with peace of mind.

Related Tools

JSON Formatter Format and validate JSON with syntax highlighting Password Generator Generate secure random passwords with one click UUID Generator Generate UUID v4 in bulk with format options ASCII Converter Convert between text and ASCII/Unicode codes Base64 Encoder Encode and decode text or files to Base64

Popular Tools

Character Counter Count characters, words, and lines in real-time QR Code Generator Create custom QR codes with logo, colors & styles IP Address Checker Check your global IP address Percent Calculator Calculate percentages easily Image Converter Convert between PNG, JPG, and WebP formats Image Compressor Compress PNG, JPEG, WebP images to reduce file size