Four Decimal Places Rounding Tool

Enter Number

Common Examples: Rounding to 4 Decimal Places

Original Number	Rounded to 4 Decimals	Explanation
3.141592653	3.1416	Fifth decimal (9) ≥ 5, rounds up
12.3456789	12.3457	Fifth decimal (7) ≥ 5, rounds up
0.123456789	0.1235	Fifth decimal (5) rounds up
2.718281828	2.7183	Fifth decimal (1) < 5, rounds down
99.99999	100.0000	Rounds up to 100
1.414213562	1.4142	Fifth decimal (1) < 5, rounds down

How to Round to 4 Decimal Places

Rounding to four decimal places means keeping exactly four digits after the decimal point. This high precision level is essential in advanced scientific calculations, precise engineering work, financial derivatives, and mathematical research where extreme accuracy is required.

Why Round to 4 Decimal Places?

High Precision Science: Advanced laboratory measurements and analysis
Engineering: Precision machining, aerospace, and technical specifications
Financial Markets: Currency trading, derivatives, and forex rates
Mathematical Constants: Pi, e, phi, and other irrational numbers
Statistical Analysis: Precise p-values, coefficients, and probability

Step-by-Step Rounding Process

Step 1: Identify the Fourth Decimal Place

In the number 3.141592653, the fourth decimal place is "5" (the ten-thousandths position).

Step 2: Look at the Fifth Decimal

The fifth decimal digit determines rounding direction. In 3.141592653, the fifth decimal is "9".

Step 3: Apply the Rounding Rule

If the fifth decimal is 5 or greater, round UP. If less than 5, round DOWN. Since 9 ≥ 5, round up to 3.1416.

Step 4: Keep Exactly Four Decimals

Drop all digits after the fourth decimal place. Final result: 3.1416

Common Use Cases

Pi (π): 3.141592653... rounds to 3.1416 for precise calculations

Euler's Number (e): 2.718281828... rounds to 2.7183

Forex Trading: EUR/USD rate 1.12345 rounds to 1.1235

Scientific Measurements: 9.806650 m/s² (gravity) rounds to 9.8067

Statistical p-value: 0.045678 rounds to 0.0457

Advanced Applications

Cryptocurrency: Bitcoin and crypto exchanges often use 4-8 decimal precision

Physics: Fundamental constants like Planck's constant, speed of light

Chemistry: Precise molar masses, reaction yields, concentrations

Astronomy: Astronomical units, light-year conversions, orbital calculations

Understanding Ten-Thousandths

Place value: The ten-thousandths place represents 1/10,000 or 0.0001

Precision comparison: 4 decimals are 10× more precise than 3 decimals

Decimal positions: 1st=tenths (0.1), 2nd=hundredths (0.01), 3rd=thousandths (0.001), 4th=ten-thousandths (0.0001)

When to Use 4 Decimal Places

High-precision requirements: When 3 decimals aren't accurate enough

Financial trading: Currency pairs, stock options, derivatives

Scientific research: Published papers requiring high precision

Engineering design: Aerospace, automotive, precision manufacturing

Quick Reference

What is four decimal places? The ten-thousandths position = 1/10,000 = 0.0001 precision

Key digit: Look at the fifth decimal place (hundred-thousandths)

Standard use: Advanced science, precision engineering, financial derivatives, and mathematical research