Significant Figures Calculator
Count significant figures in any number, round to N sig figs, view digit-by-digit significance breakdown, convert to scientific notation, and compare rounding levels with a visual precision bar.
Convert numbers to and from scientific notation, perform arithmetic operations (add, subtract, multiply, divide) on scientific numbers, view engineering notation with SI prefixes, and explore magni...
| Order | Scale | Example | Your Number |
|---|---|---|---|
| 10^-15 | femto-scale | Atomic nuclei | |
| 10^-12 | pico-scale | Atoms | |
| 10^-9 | nano-scale | DNA, viruses | |
| 10^-6 | micro-scale | Bacteria, cells | |
| 10^-3 | milli-scale | Sand grains | |
| 10^0 | human-scale | Everyday objects | |
| 10^3 | kilo-scale | Buildings, mountains | |
| 10^6 | mega-scale | Cities, countries | |
| 10^9 | giga-scale | Planets | |
| 10^12 | tera-scale | Solar system | |
| 10^15 | peta-scale | Light-years | |
| 10^18 | exa-scale | Galaxies | |
| 10^24 | yotta-scale | Observable universe |
| Prefix | Symbol | Factor | Example |
|---|---|---|---|
| yotta | Y | 10^24 | 1 Ym = 1e+24 m |
| zetta | Z | 10^21 | 1 Zm = 1e+21 m |
| exa | E | 10^18 | 1 Em = 1e+18 m |
| peta | P | 10^15 | 1 Pm = 1e+15 m |
| tera | T | 10^12 | 1 Tm = 1e+12 m |
| giga | G | 10^9 | 1 Gm = 1e+9 m |
| mega | M | 10^6 | 1 Mm = 1e+6 m |
| kilo | k | 10^3 | 1 km = 1e+3 m |
| milli | m | 10^-3 | 1 mm = 1e-3 m |
| micro | μ | 10^-6 | 1 μm = 1e-6 m |
| nano | n | 10^-9 | 1 nm = 1e-9 m |
| pico | p | 10^-12 | 1 pm = 1e-12 m |
| femto | f | 10^-15 | 1 fm = 1e-15 m |
| atto | a | 10^-18 | 1 am = 1e-18 m |
| zepto | z | 10^-21 | 1 zm = 1.0000000000000001e-21 m |
| yocto | y | 10^-24 | 1 ym = 1.0000000000000001e-24 m |
The **Scientific Notation Calculator** converts numbers between standard decimal form and scientific notation, performs arithmetic on very large or very small numbers, and helps you understand orders of magnitude. Whether you're studying physics, chemistry, astronomy, or engineering, the page keeps the notation conversion, SI-prefix context, and magnitude scale visible together.
**Three powerful modes** cover the main use cases. In conversion mode, enter any number — from everyday values to constants like Avogadro's number (6.022 × 10²³) — and see it in scientific notation, engineering notation (exponents divisible by 3), and with the appropriate SI prefix. In arithmetic mode, enter two numbers in any format (decimal or scientific) and perform addition, subtraction, multiplication, or division, with the result shown in all notation styles.
The **magnitude scale** places your number on a visual chart spanning from femto-scale (atomic nuclei) to yotta-scale (observable universe), highlighting where your number sits. The **SI prefix reference table** maps every standard prefix from yocto (10⁻²⁴) to yotta (10²⁴), automatically highlighting the prefix that matches your input.
Presets include famous physical constants — speed of light, Planck's constant, Boltzmann constant, electron mass, and Earth's mass — so you can explore real-world scientific values without retyping them. The engineering notation display is particularly useful for electrical engineers who work with values in kilo, mega, micro, and nano ranges every day.
Scientific notation problems often mix two tasks: converting the number and deciding whether the resulting scale makes sense. This calculator keeps the notation, SI prefix, engineering form, and magnitude reference together so you can check both tasks at once.
It is also useful for arithmetic with extreme values. Instead of carrying powers of ten by hand and then reformatting the result, you can compare the computed output across notation styles and confirm whether the exponent shift is reasonable.
Scientific: a × 10^n where 1 ≤ |a| < 10. Engineering: a × 10^n where n is divisible by 3. Multiply: (a×10^m)(b×10^n) = ab × 10^(m+n). Divide: (a×10^m)/(b×10^n) = (a/b) × 10^(m−n).Result: Using these inputs, the calculator computes the scientific notation answer and updates all related output cards.
This example follows the same workflow as the built-in presets: enter values, apply options, and read the computed outputs.
Use this page when a number is too large or too small to work with comfortably in ordinary decimal form, or when you need to compare several notation systems for the same value. It is useful for conversion drills, arithmetic with powers of ten, and quick checks on measurement scale.
Start with the scientific notation result, then compare the exponent, engineering form, and SI prefix. Those supporting outputs help confirm whether the number belongs in the range you expect before you use it elsewhere.
Try the conversion mode first with a familiar number, then switch to arithmetic mode and watch how multiplication and division change the exponent. That sequence makes it easier to connect the written exponent rules with the formatted outputs.
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Scientific notation expresses a number as a product of a mantissa (1 ≤ |a| < 10) and a power of 10. For example, 6,500 = 6.5 × 10³. It's used to make very large or small numbers more readable and easier to calculate with.
Engineering notation is similar to scientific notation but restricts the exponent to multiples of 3 (corresponding to SI prefixes like kilo, mega, micro, nano). So 6,500 = 6.5 × 10³ in both, but 65,000 = 65 × 10³ in engineering vs 6.5 × 10⁴ in scientific.
Multiply the mantissas and add the exponents: (3 × 10⁴)(2 × 10⁵) = 6 × 10⁹. If the resulting mantissa is ≥ 10, adjust by shifting one more power of 10.
The order of magnitude is the power of 10 when a number is expressed in scientific notation. For 5,000 (5 × 10³), the order of magnitude is 3. Two numbers are "within an order of magnitude" if they differ by less than a factor of 10.
It makes very large numbers (distance to stars) and very small numbers (atomic sizes) manageable. It also makes significant figures explicit, simplifies multiplication and division, and prevents errors from miscounting zeros.
SI prefixes are standardized names for powers of 10 used in the metric system: kilo (10³), mega (10⁶), giga (10⁹), milli (10⁻³), micro (10⁻⁶), nano (10⁻⁹), etc. They make engineering values more readable: 2.4 GHz instead of 2,400,000,000 Hz.
Count significant figures in any number, round to N sig figs, view digit-by-digit significance breakdown, convert to scientific notation, and compare rounding levels with a visual precision bar.
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