Convert between APR & APY yearly returns

Savings APR-APY conversion.js

const SECONDS_PER_YEAR = 365.25 * 24 * 60 * 60;
const BLOCKS_IN_A_YEAR = SECONDS_PER_YEAR / 14;

/**
 * Formula source: http://www.linked8.com/blog/158-apy-to-apr-and-apr-to-apy-calculation-methodologies
 *
 * @param interest {Number} APY as percentage (ie. 6)
 * @param frequency {Number} Compounding frequency (times a year)
 * @returns {Number} APR as percentage (ie. 5.82 for APY of 6%)
 */
const apyToApr = (interest, frequency = BLOCKS_IN_A_YEAR) => ((1 + (interest / 100)) ** (1 / frequency) - 1) * frequency * 100;

/**
 * Formula source: http://www.linked8.com/blog/158-apy-to-apr-and-apr-to-apy-calculation-methodologies
 *
 * @param interest {Number} APR as percentage (ie. 5.82)
 * @param frequency {Number} Compounding frequency (times a year)
 * @returns {Number} APY as percentage (ie. 6 for APR of 5.82%)
 */
const aprToApy = (interest, frequency = BLOCKS_IN_A_YEAR) => ((1 + (interest / 100) / frequency) ** frequency - 1) * 100;

thank you.