Retry backoff

Type a base, an attempt, and a multiplier. 1, 3 and 2 give 8,0000 s. 0.5, 5 and cap 10 give 10,0000 s. 2 and attempt 0 give 2,0000 s. A delay sequence, not a live client.

base × multiplier^attempt, with an optional cap. Not a live HTTP client. The window limit sits on the API Rate Limit Calculator.

Input data

Additional options (optional)

Results

Enter data and click Calculate.

How it works

Retry backoff in this calculator times a pause from a sequence. 1 s, attempt 3 and multiplier 2 give 8,0000 s. 0.5, attempt 5, ×2 and cap 10 give 10,0000 s. 2 s and attempt 0 give 2,0000 s. Formula: base × multiplier^attempt. This is not a live client.

Fields: rb-base, rb-attempt, rb-mult, optional rb-max and rb-jitter. 1 × 2^3 = 8. 0.5 × 2^5 = 16, clipped to 10. 2 × 2^0 = 2. Jitter in the second example is 20, but primary stays the cap or the delay, not a random sample.

8,0000 s does not come from axios. 10,0000 s is not Retry-After. 2,0000 s is not a live client. You type the base and the attempt. The calculator does not call an API.

API rate limit next door multiplies RPM by a window. Duration stacks hours. Here 1, 3 and 2 stay 8,0000 s, a delay sequence.

Type 1, 3 and 2, then Calculate. The result is 8,0000 s. A comma in 0,5 works. A blank attempt is a field error. This is not a live retry.

1, 3 and 2 give 8,0000 s. 0.5, 5 and cap 10 give 10,0000 s. 2 and 0 give 2,0000 s. Another attempt at 1 changes 8,0000 s.

Formula

delay = base × multiplier^attempt, then an optional cap. A sequence, not a live client.

How to use

  1. Type base 1, attempt 3, and multiplier 2.
  2. Click Calculate. The result is 8,0000 s.
  3. 0.5, 5 and cap 10 give 10,0000 s. 2 and attempt 0 give 2,0000 s.
  4. A delay sequence, not a live client.
  5. A request window sits on the API Rate Limit Calculator.

1 s, attempt 3 and ×2 = 8,0000 s

base × multiplier^attempt. 1, 3 and 2 give 8,0000 s. A sequence, not a live client.

Retry
The pause from the sequence. 1, 3 and 2 leave 8,0000 s. Not axios.
backoff
multiplier^attempt. 0.5 and 5 with cap 10 give 10,0000 s.
attempt
Field rb-attempt. 0 at base 2 leaves 2,0000 s.

Examples

Example 1

  • base 1 s
  • attempt 3
  • multiplier 2

8,0000 s

How many s at 1, attempt 3 and ×2? 8,0000 s. A delay sequence, not a live client.

Example 2

  • base 0.5 s
  • attempt 5
  • multiplier 2
  • cap 10
  • jitter 20

10,0000 s

What about 0.5, 5 and cap 10? 10,0000 s. 16 clipped to 10.

Example 3

  • base 2 s
  • attempt 0
  • multiplier 2

2,0000 s

What about 2 and attempt 0? 2,0000 s. 2^0 leaves the base.

Related calculators

Common questions

How many s at 1, attempt 3 and ×2?

8,0000 s. 1 × 2^3. A sequence, not a live client.

What about 0.5, 5 and cap 10?

10,0000 s. 0.5 × 2^5 = 16, clipped to 10.

What about 2 and attempt 0?

2,0000 s. 2 × 2^0 leaves the base.

Is this a live HTTP client?

No. Sequence fields. The calculator does not call an API and does not read 429.

Does jitter randomize 10,0000 s?

No. Jitter is a band. The result stays the cap or the delay.

Does a comma in 0,5 work?

Yes. 0,5, 5 and cap 10 give 10,0000 s.

Is 8,0000 s Retry-After?

No. A result from a base and an attempt. Not a header.

Where do I count a rate-limit window?

On the API Rate Limit Calculator. Here 8,0000 s stays.

Does a blank attempt count?

No. The attempt must be a number. Zero is legal and leaves the base.

Knowledge sources

The calculator counts bits, bytes or throughput from your numbers. Below are SI and bit definitions (NIST).

Page updated in 2026.