A Systematic Investment Plan, or SIP, is one of the most convenient and disciplined methods to build wealth through mutual fund plans. By investing a fixed amount regularly, you can build a sizeable corpus over time. SIPs work on the principle of compounding and rupee-cost averaging, which allows your money to grow steadily, even during volatile market conditions.If you're aiming to accumulate Rs 50 lakh in the next five years, SIPs can be a strategic vehicle to achieve that goal. But how much do you need to invest each month?Let’s break it down how you can build a Rs 50-lakh corpus in five years.Starting SIP At 30? Here's How Much Rs 5,000 And Rs 10,000 Monthly Can Make For RetirementHow Much Time Would You NeedTo build a corpus of Rs 50 lakh in five years, the monthly SIP amount depends on the rate of return you expect. Since equity mutual funds offer the best chance of high returns over the medium to long term, we’ll use that for our assumption.If you invest in equity mutual funds that deliver an average return of around 12% annually, you’ll need to invest close to Rs 61,000 per month for five years to reach your Rs 50-lakh goal.In a more conservative scenario, assuming a 10% annual return, your monthly SIP requirement would go up slightly. It would come to around Rs 65,000 per month to accumulate Rs 50 lakh.On the other hand, if the markets perform very well and your fund delivers around 15% annually, you could reach the goal with a slightly lesser amount, around Rs 56,000 per month.The key takeaway? You’ll need to be consistent, disciplined and comfortable investing over Rs 60,000 each month.Why SIPs Work For Goal-Based InvestingThe advantage of SIPs lies in their market-linked returns and flexibility. You buy mutual fund units at different price points, which averages out the cost over time. Also, SIPs encourage a savings habit that aligns well with financial goals like education, a house purchase, or in this case, building a Rs 50 lakh corpus.Another important factor is compounding. Your returns get reinvested, allowing you to earn returns on both your capital and past gains. Even with a five-year horizon, this compounding effect plays a major role.Avoid the temptation to chase short-term trends. Instead, pick funds based on long-term performance, consistency, expense ratio and risk profile. You can use an online SIP calculator to estimate the monthly investment amount based on different assumptions.What If You Can’t Invest Rs 60,000 Per Month?Everyone may not be able to invest such a large amount monthly. If that’s the case, don’t worry. You can adjust the time frame.If you extend your investment horizon to seven or 10 years, your SIP amount will come down significantly. The longer you remain invested, the more compounding works in your favour. Starting early, even with a smaller amount, is always better than waiting to save a lump sum later.Also, you can consider gradually increasing your SIP amount each year in line with salary increments. This is known as a step-up SIP and can help you bridge the gap between what you can afford today and what you need to reach your goal.How To Build Rainy-Day Fund With SIP: Rs 1,000 To Rs 10,000 A Month Investment Plans. Read more on Personal Finance by NDTV Profit.