Scientific Notation Calculator
Convert to and from scientific notation. Do arithmetic in scientific notation with step-by-step working. Includes engineering notation.
Convert numbers between standard form and scientific notation, perform arithmetic on numbers in scientific notation, and see engineering notation with SI prefixes. Every conversion shows step-by-step working in both directions.
About Scientific Notation Calculator
What Is Scientific Notation?
Scientific notation expresses a number as a coefficient between 1 and 10 multiplied by a power of 10:
a × 10^n where 1 ≤ a < 10
How to convert: Move the decimal point until you have a number between 1 and 10. The number of places you moved is the exponent. Moving left gives a positive exponent (large numbers); moving right gives a negative exponent (small numbers).
Worked example: Convert 6,370,000 to scientific notation
- Place the decimal after the first digit: 6.370000
- Count how many places the decimal moved: 6 places to the left
- Result: 6.37 × 10^6
Worked example: Convert 0.0000042 to scientific notation
- Place the decimal after the first non-zero digit: 4.2
- Count how many places the decimal moved: 6 places to the right
- Result: 4.2 × 10^(-6)
Conversion Reference Table
| Standard Form | Scientific Notation | Name |
|---|---|---|
| 1,000,000,000 | 1 × 10^9 | One billion |
| 1,000,000 | 1 × 10^6 | One million |
| 1,000 | 1 × 10^3 | One thousand |
| 1 | 1 × 10^0 | One |
| 0.001 | 1 × 10^(-3) | One thousandth |
| 0.000001 | 1 × 10^(-6) | One millionth |
| 0.000000001 | 1 × 10^(-9) | One billionth |
How to Do Arithmetic in Scientific Notation
The rules differ for multiplication/division vs addition/subtraction:
Multiplication: Multiply coefficients, add exponents
- (3 × 10^4) × (2 × 10^5) = 6 × 10^9
Division: Divide coefficients, subtract exponents
- (8 × 10^7) / (4 × 10^3) = 2 × 10^4
Addition/Subtraction: First make the exponents the same, then add or subtract the coefficients
- (3.5 × 10^4) + (2.1 × 10^3) = (3.5 × 10^4) + (0.21 × 10^4) = 3.71 × 10^4
Detailed worked example (multiplication): Calculate (4.2 × 10^3) × (3.0 × 10^(-5))
- Multiply coefficients: 4.2 × 3.0 = 12.6
- Add exponents: 3 + (-5) = -2
- Intermediate: 12.6 × 10^(-2)
- Normalise (coefficient must be 1-10): 1.26 × 10^(-1)
- Standard form: 0.126
Engineering Notation and SI Prefixes
Engineering notation restricts the exponent to multiples of 3, which maps directly to SI prefixes:
| SI Prefix | Symbol | Power of 10 | Example |
|---|---|---|---|
| Tera | T | 10^12 | 1 TB = 1 × 10^12 bytes |
| Giga | G | 10^9 | 2.4 GHz = 2.4 × 10^9 Hz |
| Mega | M | 10^6 | 5 MW = 5 × 10^6 watts |
| Kilo | k | 10^3 | 47 kΩ = 4.7 × 10^4 ohms |
| Milli | m | 10^(-3) | 250 mL = 2.5 × 10^(-1) litres |
| Micro | μ | 10^(-6) | 10 μF = 1 × 10^(-5) farads |
| Nano | n | 10^(-9) | 5 nm = 5 × 10^(-9) metres |
| Pico | p | 10^(-12) | 22 pF = 2.2 × 10^(-11) farads |
Engineering notation is standard practice in electronics, physics, and engineering because the prefixes are immediately meaningful. "4.7 × 10^3 ohms" becomes "4.7 kΩ" at a glance.
Famous Constants in Scientific Notation
| Constant | Value | Scientific Notation |
|---|---|---|
| Speed of light | 299,792,458 m/s | 2.998 × 10^8 m/s |
| Avogadro's number | 602,214,076,000,000,000,000,000 | 6.022 × 10^23 |
| Planck's constant | 0.000000000000000000000000000000000663 | 6.63 × 10^(-34) J·s |
| Electron mass | 0.000000000000000000000000000000911 | 9.11 × 10^(-31) kg |
| Boltzmann constant | 0.0000000000000000000000138 | 1.38 × 10^(-23) J/K |
| Earth's mass | 5,972,000,000,000,000,000,000,000 kg | 5.972 × 10^24 kg |
Without scientific notation, numbers at these extremes are nearly impossible to read, compare, or compute with.
Scientific Notation and Significant Figures
One major advantage of scientific notation is that it removes ambiguity about significant figures. The number 4500 could have 2, 3, or 4 sig figs. But 4.5 × 10^3 clearly has 2, while 4.500 × 10^3 clearly has 4. For counting and rounding significant figures, the sig figs calculator handles any number.
Orders of Magnitude
The exponent in scientific notation gives the "order of magnitude" - a rough measure of size. Two numbers are said to differ by one order of magnitude if one is about 10 times the other.
| Object/Distance | Size | Order of Magnitude (m) |
|---|---|---|
| Proton diameter | ~1 fm | 10^(-15) |
| Atom diameter | ~0.1 nm | 10^(-10) |
| Human hair width | ~75 μm | 10^(-5) |
| Human height | ~1.7 m | 10^0 |
| Earth diameter | ~12,742 km | 10^7 |
| Sun diameter | ~1.39 million km | 10^9 |
| Light-year | ~9.46 trillion km | 10^16 |
For exponent calculations directly, the exponent calculator computes any base raised to any power. For handling error in scientific measurements, the percent error calculator compares experimental to theoretical values.
Where Did Scientific Notation Come From?
Scientific notation as we know it became standard in the 17th century alongside the rise of logarithm tables, but the idea of writing very large numbers as multiples of powers of 10 goes back to Archimedes. In The Sand Reckoner (c. 250 BCE), Archimedes set out to calculate the number of grains of sand needed to fill the universe and invented a place-value system based on myriads (10,000) to handle the arithmetic - effectively the first documented exponential notation. The modern notation with the "×10^n" form was popularised by French mathematicians in the 1800s and became the default in textbooks and scientific papers after the adoption of the SI system in 1960.
The notation is now codified in international standards. ISO 80000-1:2022 specifies scientific notation as the preferred form for expressing the numerical values of physical quantities, and IUPAC recommends it for all chemistry publications when numbers span more than two orders of magnitude.
How Are Scientific and Engineering Notation Used in Real Work?
The choice between scientific and engineering notation usually comes down to the field and the reader. Physicists and chemists tend to stick with pure scientific notation because keeping the coefficient between 1 and 10 makes it easy to compare magnitudes at a glance. Electrical engineers and computer hardware designers use engineering notation because the exponents line up directly with the SI prefix system (kilo, mega, giga, tera) that is already stamped on every component and datasheet.
Where you will see each in practice:
- Astronomy: distances are almost always given in scientific notation - the Sun is 1.496 × 10^11 m from Earth, the observable universe has a radius of about 4.4 × 10^26 m.
- Chemistry: molar quantities and reaction rates are pure scientific notation. The Avogadro constant, exactly 6.02214076 × 10^23 mol^(-1) since the 2019 SI redefinition, is perhaps the most cited number in the field.
- Electronics: capacitors, resistors, and clock speeds use engineering notation. A 2.2 kΩ resistor is never written as 2.2 × 10^3 Ω on a schematic.
- Computing: file sizes are given in binary-aligned engineering notation (KB, MB, GB) but with decimal prefixes - an 8 TB drive is 8 × 10^12 bytes in SI marketing terms, or 7.27 TiB in binary terms.
- Biology: cell counts, gene lengths, and enzyme concentrations span 20+ orders of magnitude. Human genome base pairs (~3.1 × 10^9) and a typical bacterial cell diameter (~1 × 10^(-6) m) would be unreadable otherwise.
Common Mistakes to Avoid
Scientific notation arithmetic is simple once the rules are internalised, but a few traps catch students and working scientists alike.
- Forgetting to normalise after multiplying or adding. (7 × 10^5) × (8 × 10^3) = 56 × 10^8, but the correct answer is 5.6 × 10^9. The coefficient must always end up between 1 and 10.
- Trying to add without matching exponents. You cannot directly add 3 × 10^5 and 4 × 10^2. Shift one so the exponents match (0.004 × 10^5 + 3 × 10^5 = 3.004 × 10^5) before adding the coefficients.
- Mixing up the sign of the exponent. Moving the decimal to the right (small numbers) gives a negative exponent. 0.00056 = 5.6 × 10^(-4), not 10^4. A good sanity check: if the original number is less than 1, the exponent is negative.
- Losing significant figures. When you type 4.500 × 10^3, the three trailing zeros are significant. If you round to 4.5 × 10^3 for display, you have silently discarded precision. See the sig figs calculator for the full rounding rules.
- Confusing E notation with ×10^n. Calculators and programming languages use "E" or "e" for the exponent (3.5E6 means 3.5 × 10^6). "E" is not Euler's number in this context - it is purely a separator.
- Assuming floating-point arithmetic is exact. IEEE 754 double precision, used by JavaScript and most calculators, has about 15-17 significant decimal digits. Operations on numbers with very different exponents can lose precision - (1 × 10^20) + 1 evaluates to exactly 10^20 in double precision because the "1" falls off the end of the mantissa.
Scientific Notation in Programming
Most programming languages represent scientific notation using the "e" or "E" separator. 3.5e6 in JavaScript, Python, C, and SQL all mean 3.5 × 10^6. The IEEE 754 double-precision floating-point format underpins almost all of these: it uses 1 bit for sign, 11 bits for the exponent, and 52 bits for the mantissa, giving a range of roughly 5 × 10^(-324) to 1.8 × 10^308 with about 15-17 significant decimal digits of precision.
This has real consequences for everyday code. 0.1 + 0.2 in JavaScript returns 0.30000000000000004, not because the maths is wrong but because 0.1 and 0.2 cannot be represented exactly in binary floating point. When precise decimal arithmetic matters - accounting, currency, tax - use a decimal library or integer arithmetic on the smallest unit (pence, cents) rather than floating-point scientific notation.
Sources
- NIST - CODATA Recommended Values of the Fundamental Physical Constants
- BIPM - SI Brochure (9th edition, SI prefixes and scientific notation)
- ISO 80000-1:2022 - Quantities and units (scientific notation conventions)
- IUPAC - Recommendations on numerical notation in chemistry
- IEEE 754-2019 - Standard for Floating-Point Arithmetic
- Wolfram MathWorld - Scientific Notation
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Frequently Asked Questions
What is scientific notation?
Scientific notation expresses numbers as a coefficient between 1 and 10 multiplied by a power of 10. For example, 3,500,000 becomes 3.5 x 10^6. It makes very large or very small numbers easier to work with.
What is engineering notation?
Engineering notation is similar to scientific notation but restricts the exponent to multiples of 3. This aligns with SI prefixes like kilo (10^3), mega (10^6), and giga (10^9), making it practical for engineering work.
How do I enter scientific notation?
Type the coefficient, then x or *, then 10^, then the exponent. For example: 3.5 x 10^6 or 2.1x10^-3. Spaces are optional.
Can I do math with scientific notation?
Yes. The Arithmetic tab lets you add, subtract, multiply, or divide two numbers in scientific notation. Results are shown in both scientific notation and standard form.
How do I convert from scientific notation to a regular number?
Enter the scientific notation in the right input box (e.g. 6.022 x 10^23). The calculator shows the full standard number alongside the engineering notation equivalent.
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