Hexadecimal to Octal Converter

Step 1 — Identify the symbols

Input (Hexadecimal): Digits 0–9 plus letters A–F for values ten through fifteen.

Output (Octal): Each digit is 0–7 (eight possibilities per position).

Hex conversions use this letter-to-number map:

Step 2 — The Two-Step Method (via Decimal)

Part A — Into decimal

Number positions from the right, starting at 0. At each position, multiply that digit by 16 raised to the position index, then add every term. The total is your decimal number.

Digits after the dot: use negative powers of 16 (16⁻¹, 16⁻², …). Each place is still (digit × weight); add the fractional side to the whole side.

A–F reminder: treat A as 10, B as 11, …, F as 15 when you multiply by powers of 16 (see Step 1 table).

Part B — Out of decimal

Repeated division by 8: same idea as binary, but divide by 8 each time. Remainders are octal digits (0–7), read bottom-up.

Fractional decimal values: convert the whole part with repeated division, then multiply the fractional part by the target base over and over; each integer you get is the next digit after the radix point (same idea the calculator shows in Formulas).

Step 3 — Worked examples

Two practice values in Hexadecimal, converted to Octal using the same rules as Step 2. Example 3 uses a fractional part (digits after the radix point); the hub and pair calculators accept a single . on binary, octal, decimal, and hex inputs.

Hexadecimal "1A"
= 1×16¹ + A×16⁰
= 16 + 10
= 26  (decimal)

Whole part — repeated division:
26 ÷ 8 = 3  R 2
3 ÷ 8 = 0  R 3

Read remainders bottom → top → 32

→ tool: 032

Hexadecimal "FF"
= F×16¹ + F×16⁰
= 240 + 15
= 255  (decimal)

Whole part — repeated division:
255 ÷ 8 = 31  R 7
31 ÷ 8 = 3  R 7
3 ÷ 8 = 0  R 3

Read remainders bottom → top → 377

→ tool: 0377

Hexadecimal "A.8"
Left of . : A×16⁰ = 10
Right of .: 8×16^-1 = 0.5
= 10.5  (decimal)

Whole part — repeated division:
10 ÷ 8 = 1  R 2
1 ÷ 8 = 0  R 1

Read remainders bottom → top → 12

Fractional part — multiply by 8, integer of each product = next digit after .
  0.5×8 = 4  →  4
Digits after . (in order): .4

→ tool: 012.4