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Number Systems & Educational Calculations

Binary to Decimal Converter with Steps

Convert binary numbers to decimal with step-by-step mathematical explanations, powers of 2 breakdown, positional bit tables, and BigInt precision.

  • Processed locally
  • No upload required
  • No account required

Accepts binary digits (0 and 1), optional negative sign (-), spaces, underscores, or 0b prefix.

Samples:

Decimal Result (Base-10)

45

Converted from 6 binary bits with BigInt precision.

Hexadecimal

0x2D

Octal

0o55

Bit Length

6 bits

Set Bits (1s)

4

Step-by-Step Mathematical Calculation

Step 1: Expand as Positional Powers of 2

101101₂ =

(1×2⁵ + 0×2⁴ + 1×2³ + 1×2² + 0×2¹ + 1×2⁰)

Step 2: Evaluate the Individual Powers of 2

= (32 + 0 + 8 + 4 + 0 + 1)

Step 3: Sum the Evaluated Terms

= 45

Positional Bit Breakdown Table

Bit PositionBinary DigitPower of 2Decimal WeightTerm CalculationContribution
2^512^5321 × 3232
2^402^4160 × 160
2^312^381 × 88
2^212^241 × 44
2^102^120 × 20
2^012^011 × 11

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About Binary to Decimal Converter with Steps – Step-by-Step Calculator

Convert binary numbers (base-2) into decimal values (base-10) with an educational step-by-step breakdown.

Inspect positional powers of 2, polynomial expansion formulas, bit contribution tables, and hexadecimal representations.

Input is processed locally in your browser and is not sent to Navorika.

How the calculation works

Positional Notation

Each binary digit d at position n (from right, 0-indexed) represents d × 2^n in base 10.

Polynomial Summation

The total decimal value equals the sum of all active bit weights: Value = ∑ (b_i × 2^i) for i from 0 to N-1.

How to use this tool

  1. 1Enter a binary number (e.g. 101101) or choose a sample value.
  2. 2Review the evaluated decimal result computed using BigInt arbitrary-precision arithmetic.
  3. 3Examine the step-by-step polynomial expansion formula and evaluated powers of 2.
  4. 4Inspect the positional bit breakdown table showing the weight and contribution of each bit.

Understanding the result

Bits set to 1 add their positional power of 2 (1, 2, 4, 8, 16, 32...) to the decimal total.

Bits set to 0 contribute zero to the final summation.

Important limitations

  • Fractional binary values (e.g. 101.101) are not covered; this tool focuses on integer representations.
  • Inputs with thousands of bits are calculated accurately via BigInt but formulas are abbreviated for display.

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Frequently asked questions

How is 101101 converted to decimal?

101101₂ = 1×2⁵ + 0×2⁴ + 1×2³ + 1×2² + 0×2¹ + 1×2⁰ = 32 + 0 + 8 + 4 + 0 + 1 = 45.

Does this calculator handle large binary numbers?

Yes. The calculation engine uses JavaScript BigInt to prevent 53-bit floating-point precision loss.

Can I include spaces or the 0b prefix in my input?

Yes. Visual separators like spaces, underscores, and standard 0b prefixes are automatically stripped.

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