A recent study found that more than a third of Millennials ages 24 to 35 have less than $1,000 in Savings, and just 15% have more than $10,000. How much you should have in your savings is dictated largely by your lifestyle and your goals: You should have enough in savings to cover all of your living expenses — rent, bills, and food — for at least three months.

Some sources recommend six months of savings for extra security. That means, if you’re paying $900 for rent, $200 for food, and $300 for bills (cell phone, utilities, loan payments) on a monthly basis, you’ll want to have nearly $8,500 in your savings account. If you have any additional financial goals, like saving for a new car, house, or retirement, you’ll need to save more on top of that emergency cushion.

So, where to begin? The best way to start building up your savings is by regulating your spending. That means, yes, it’s time to build a budget.

Calculate Your Income & Expenses

Start by calculating your monthly income. Then, go through your last month’s bank account statement and add up 30 days of bills and related expenses, such as food and household supplies, and decide how much you want to spend as your “free” money each month for things like entertainment or eating out. Subtract all of those expenses from your income, and plan to save the rest. If that’s not quite as much as you’d like to save, recalculate your expenses including your goal savings amount as a non-negotiable bill, and use the leftover cash as your “free” money.

Use The 50/30/20 Rule

Alternately, and perhaps more harshly, you could subscribe to the 50/30/20 rule, which rigidly dictates the percentage of your income spent on different expense categories: Spend 50% of your income on the essentials (think: housing costs, food, utilities, and other bills), 30% on personal expenses (more discretionary items such as your cellphone or cable bills, shopping, and entertainment), and save the last 20%. According to Charles Schwab, tucking 15% to 20% of your income away for retirement before age 30 will likely prevent you from having to save more than 20% later down the line.

Use An App

If you’ve tried this before but still struggle with your spending, try putting your bill due dates into a calendar app. This will help you visualize your expenses, giving you a better idea of when is an OK time to spend money, and when things might get a little tight. Also schedule automatic transfers from your checking to your savings, and make sure those dates are in your calendar as well. Use the calendar to pick a date that won’t interfere with other expenses. It’s easier to save when you don’t have to remember to do it.

Use Cash Instead

To keep your budget set in stone, try ditching the plastic for cash. Instead of swiping your card at will, go to the bank and withdraw cash for your food and entertainment budgets. When you’re out of money, you’re out of the game. (If you want to be really stringent, you can keep the cash in separate envelopes.)