The incoming requirements will apply to 8,000 businesses and 11 million employees, allowing managers to see the difference in the average salary of their male and female employees.
ONS figures show that the gender pay gap is currently 9.4%, and it is thought that by reducing this gap, companies could benefit from higher productivity and an enhanced reputation as a fair employer.
Acas chief executive, Anne Sharp, said: “The new requirement provides a great opportunity for organisations to look at the issue in depth and to consider whether they can do more to develop their talented women and secure the benefits of greater gender diversity at all levels.
"The UK has made progress in reducing the gender pay gap but we still have lots to do - tackling the issue is in the interests of individuals, organisations and the economy as a whole.
"Our new guidance on gender pay reporting provides businesses with practical advice on how to carry out the calculations and on family friendly working to reduce the gap."
A report by McKinsey & Co in September last year showed that eliminating work-related gender pay gaps could add £150bn to annual UK GDP by 2025, however another report found that current trends indicate the gap is unlikely to narrow until 2069.
The new guidance includes:
• How to monitor gender differences in the recruitment balance, starting salaries, promotions, and flexible working requests across all job types and levels in the hierarchy
• How best to promote family friendly working so women can balance work and parental responsibilities, especially for senior roles
• Encourages men to use flexible working so they share the responsibility of balancing work and a family life
• How to correctly count the number of employees for the gender pay gap calculations
• How and where a business must publish the data from the gender pay gap
• The penalties if businesses don't comply.
Minister for women, equalities and early years, Caroline Dinenage, said: “No one should ever be held back just because of their gender. We now have the lowest gender pay gap on record, but we still have to push further.
"Shining a light on the gaps is absolutely key to achieving equality in the workplace, which is why we are introducing requirements on all large employers to publish their gender pay and bonus data from April.
"I encourage all employers to use this guidance, which will be an important and helpful tool for tackling the gender pay gap and promoting workplace equality."
You can view the latest gender pay gap reporting guidance here.