Doubling time / Rule of 72

Code snippets

curl "https://api.oanor.com/cagr-api/v1/doubling-time" \
  -H "x-oanor-key: oanor_test_..."

await fetch("https://api.oanor.com/cagr-api/v1/doubling-time", {
  headers: { "x-oanor-key": "oanor_test_..." }
});

$ch = curl_init("https://api.oanor.com/cagr-api/v1/doubling-time");
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$out = curl_exec($ch);

import requests
requests.get(
    "https://api.oanor.com/cagr-api/v1/doubling-time",
    headers={"x-oanor-key": "oanor_test_..."}
)

Example response

A real response from this endpoint, captured by the latest health check.

{
    "data": {
        "note": "Doubling time: exact = ln2/ln(1+r). The Rule of 72 (72/rate%) is a handy estimate — at 8 % money doubles in about 9 years.",
        "inputs": {
            "rate_percent": 8
        },
        "rule_of_70": 8.75,
        "rule_of_72": 9,
        "exact_years": 9.006468,
        "rule_of_69_3": 8.6625
    },
    "meta": {
        "timestamp": "2026-06-05T19:50:25.654Z",
        "request_id": "937563f2-9d53-465e-bb80-c78ec00d3ab5"
    },
    "status": "ok",
    "message": "Doubling time",
    "success": true
}