How to calculate money needed for bills, by day
I think you might benefit from adopting a zero-sum budget, in which you plan where each dollar will be spent ahead of time, rather than simply track spending or worry about the next expense. Here's a pretty good article on the subject: How and Why to Use a Zero-Sum Budget. This is the philosophy behind a popular budgeting tool You Need a Budget, I am not advocating the tool, but I am a fan of the idea that a budget is less about tracking spending and more about planning spending. That said, to answer your specific question, one method for tracking your min-needed for upcoming expenses would be to record the date, expense, amount due, and amount paid as shown here:  Then the formula to calculate the min-needed (entered in E1 and copied down) would be: As you populate amounts paid, the MinNeeded is adjusted for all subsequent rows. You could get fancier and only populate the MinNeeded field on dates where an expense is due using IF(). If I understand you right, what you need is the minimum amount in the account until your next deposit.  So for example, if today is the 10th and you get paid on the 15th, how much do I need to have in the account, so I know how much I can spend?  That amount should be all of the bills that will be paid between today and the 15th. An alternative would just to keep a running balance and see what the minimum value is. My personal finance software does that for me, but it's possible, although a little more complicated, in Excel.  You'd have to find the date of the next deposit, and do a SUMIF looking for dates between today and that date.  That's about as far as I can get without getting off-topic. "Trying to figure out how much money you have available each day sounds like you're making this more complicated than it needs to be. Unless you're extremely tight and you're trying to squeeze by day by day, asking ""do I have enough cash to buy food for today?"" and so on, you're doing too much work. Here's what I do. I make a list of all my bills. Some are a fixed amount every month, like the mortgage and insurance premiums. Others are variable, like electric and heating bills, but still pretty predictable.  Most bills are monthly, but I have a few that come less frequently, like water bills in my area come every 3 months and I have to pay property taxes twice a year. For these you have to calculate how much they cost each month. Like for the water bill, it's once every 3 months so I divide a typical bill by 3. Always round up or estimate a little high to be safe. Groceries are a little tricky because I don't buy groceries on any regular schedule, and sometimes I buy a whole bunch at once and other times just a few things. When groceries were a bigger share of my income, I kept track of what I spent for a couple of months to figure out an average per month. (Today I'm a little richer and I just think of groceries as coming from my spending money.) I allocate a percentage of my income for contributions to church and charities and count this just like bills. It's a good idea to put aside something for savings and/or paying down any outstanding loans every month. Then I add these up to say okay, here's how much I need each month to pay the bills. Subtract that from my monthly income and that's what I have for spending money. I get paid twice a month so I generally pay bills when I get paid. For most bills the due date is far enough ahead that I can wait the maximum half a month to pay it. (Worst case the bill comes the day after I pay the bills from this paycheck.)  Then I keep enough money in my checking account to, (a) Cover any bills until the next paycheck and allow for the particularly large bills; and (b) provide some cushion in case I make a mistake -- forget to record a check or make an arithmetic error or whatever; and (c) provide some cushion for short-term unexpected expenses. To be safe, (a) should be the total of your bills for a month, or as close to that as you can manage. (b) should be a couple of hundred dollars if you can manage it, more if you make a lot of mistakes. If you've calculated your expenses properly and only spend the difference, keeping enough money in the bank should fall out naturally. I think it's a lot easier to try to manage your money on a monthly basis than on a daily basis. Most of us don't spend money every day, and we spend wildly different amounts from day to day. Most days I probably spend zero, but then one day I'll buy a new TV or computer and spend hundreds.  Update in response to question What I do in real life is this: To calculate my available cash to spend, I simply take the balance in my checking account -- assuming that all checks and electronic payments have cleared. My mortgage is deducted from my checking every month so I post that to my checking a month in advance. I pay a lot of things with automatic charges to a credit card these days, so my credit card bills are large and can't be ignored. So subtract my credit card balances. Subtract my reserve amount. What's left is how much I can afford to spend. So for example: Say I look at the balance in my checkbook today and it's, say, $3000. That's the balance after any checks and other transactions have cleared, and after subtracting my next mortgage payment. Then I subtract what I owe on credit cards. Let's say that was $1,200. So that leaves $1,800. I try to keep a reserve of $1,500. That's plenty to pay my routine monthly bills and leave a healthy reserve. So subtract another $1,500 leaves $300. That's how much I can spend. I could keep track of this with a spreadsheet or a database but what would that gain? The amount in my checking account is actual money. Any spreadsheet could accumulate errors and get farther and farther from accurate values. I use a spreadsheet to figure out how much spending money I should have each month, but that's just to use as a guideline. If it came to, say, $100, I wouldn't make grandiose plans about buying a new Mercedes. If it came to $5,000 a month than buying a fancy new car might be realistic. It also tells me how much I can spend without having to carefully check balances and add it up. These days I have a fair amount of spending money so when, for example, I recently decided I wanted to buy some software that cost $100 I just bought it with barely a second thought. When my spending money was more like $100 a month, lunch at a fast food place was a big event that I planned weeks in advance. (Obviously, I hope, don't get stupid about ""small amounts"". If you can easily afford $100 for an impulse purchase, that doesn't mean that you can afford $100 five times a day every day.) Two caveats: 1. It helps to have a limited number of credit cards so you can keep the balances under control. I have two credit cards I use for almost everything, so I only have two balances to keep track of. I used to have more and it got confusing, it was easy to lose track of how much I really owed, which is a set up for getting in trouble."
Risk. Volatility. Liquidity. Etc.  All exist on a spectrum, these are all comparative measures.  To the general question, is a mutual fund a good alternative to a savings account? No, but that doesn't mean it is a bad idea for your to allocate some of your assets in to one right now. Mutual funds, even low volatility stock/bond blended mutual funds with low fees still experience some volatility which is infinitely more volatility than a savings account.  The point of a savings account is knowing for certain that your money will be there.  Certainty lets you plan. Very simplistically, you want to set yourself up with a checking account, a savings account, then investments.  This is really about near term planning.  You need to buy lunch today, you need to pay your electricity bill today etc, that's checking account activity.  You want to sock away money for a vacation, you have an unexpected car repair, these are savings account activities.  This is your foundation.  How much of a foundation you need will scale with your income and spending.   Beyond your basic financial foundation you invest.  What you invest in will depend on your willingness to pay attention and learn, and your general risk tolerance. Sure, in this day and age, it is easy to get money back out of an investment account, but you don't want to get in the habit of taping investments for every little thing. Checking: No volatility, completely liquid, no risk Savings: No volatility, very liquid, no principal risk  Investments: (Pick your poison) The point is you carefully arrange your near term foundation so you can push up the risk and volatility in your investment endeavors.  Your savings account might be spread between a vanilla savings account and some CDs or a money market fund, but never stock (including ETF/Mutual Funds and blended Stock/Bond funds). Should you move your savings account to this mutual fund, no.  Should you maybe look at your finances and allocate some of your assets to this mutual fund, sure.  Just look at where you stand once a year and adjust your checking and savings to your existing spending.  Savings accounts aren't sexy and the yields are awful at the moment but that doesn't mean you go chasing yield.  The idea is you want to insulate your investing from your day to day life so you can make unemotional deliberate investment decisions. "The real question is what can you NOT do!  If you track all your monetary actions, you know everything about your monetary situation.  That means you have the tools to ask and answer ""what if"" questions, such as: ""If I get a 10% raise, could I take longer vacations?""  You could calculate how much you spend per day on vacation and then consider the amount of your raise and how much of it you'd need to allocate to vacations to, say, be able to take a two-week vacation instead of a one-week vacation. ""How much more would I have to earn to move to this nicer apartment?""  This may seem like a simple question, but a surprising number of people can't answer it in a reliable way, because they don't have a clear understanding of how much money they make and how much of it they can afford to spend on housing.  If you find you have lots of spare income, maybe you can move to the nicer place right away; if not, at least you can get a sense of how much more money you'd need to make it happen. ""If I started taking the bus to work, how much would I save?""  You can look at how much you spend on gas and compare that to the price of a bus pass.  By separating out categories like gas, repairs, and car insurance, you can also calculate different scenarios, like if you still kept your car but only used it for occasional trips, versus if you sold the car and used only public transportation. ""If I want to take a trip to Tahiti, what can I cut back on to save the money?""  Using your table you can pencil out scenarios like ""Suppose I stop eating out for lunch at work and just bring my lunch, how long would I have to do that to save enough to pay for a plane ticket?"" These are just a few random examples.  The general idea is that with a record of hard numbers, you can start to consider potential tradeoffs in an objective way --- that is, you can ask ""how much in category X would I have to give up to gain this thing I want in category Y?"" The real trick in making use of your data is not so much ""what"" you can do, but ""how"" exactly to do it.  You may have to become more of a spreadsheet wizard to really delve into these questions.  Also, if you have programming expertise, you can even use something like Python to do calculations that might be laborious in a spreadsheet." "I opened several free checking accounts at a local credit union.  One is a ""Deposit"" account where all of my new money goes.  I get paid every two weeks.  Every other Sunday we have our ""Money Day"" where we allocate the money from our Deposit account into our other checking accounts.  I have one designated as a Bills account where all of my bills get paid automatically via bill pay or auto-pay. I created a spreadsheet that calculates how much to save each Money Day for all of my upcoming bills.  This makes it so the amount I save for my bills is essentially equal.  Then I allocate the rest of my deposit money into my other checking accounts.  I have a Grocery, Household, and Main checking accounts but you could use any combination that you want. When we're at the store we check our balances (how much we have left to spend) on our mobile app.  We can't overspend this way.  The key is to make sure you're using your PIN when you use your debit card.  This way it shows up in real-time with your credit union and you've got an accurate balance.  This has worked really well to coordinate spending between me and my wife.  It sounds like it's a lot of work but it's actually really automated.  The best part is that I don't have to do any accounting which means my budget doesn't fail if I'm not entering my transactions or categorizing them. I'm happy to share my spreadsheet if you'd like." To point #1: We are moving but I don't know If I can afford the rent as the family grows I would start by looking at your debt-to-income ratio. In the US, most banks look at this for mortgage purposes, but it also gives you a general idea of what monthly mortgage payments will be comfortable given your particular financial situation. Think of it this way, if a bank is unwilling to lend you money because of a high debt-to-income level, this indicates that you have very little leeway with regard to your budget. So a lower number indicates that you will have more flexibility and comfort with meeting your rent/mortgage obligations when unforeseen bills pop up. The article below indicates having < 43% DTI is ideal (in the US). Here's a link to a debt to income calculator and some extra info (I suggest finding one aimed at the UK market): WellsFargo debt to income calculator Why is the 43% debt to income ratio important? Point #2: How can a person measure how much to spend on food, car, bills or rent from his salary? Is there a formula to keep in check? Other answers have addressed how to make a budget, so I will not repeat that. However, here's another angle with regards to spending/saving. This article recommends 50/30/20: According to the popular 50/30/20 rule, you should reserve 50 percent of your budget for essentials like rent and food, 30 percent for discretionary spending, and at least 20 percent for savings. Read more at: https://www.moneyunder30.com/how-much-should-you-save-every-month-2 In the real world, these goals may not be realistic, and different people have different ideas about how aggressive to be with regards to savings. However, you can get a general idea and adapt for your particular needs. Point 3: I find myself looking at my account every single day and get tensed and sad because almost whenever the money (pay) comes in I freak out that after everything there is nothing for us to enjoy or save. Ok well in that case here are my thoughts.  Its been a while since I've done this type of school work so hope it's right/helpful.  AR Oustanding = Avg AR / (credit sales/Operating Cycle*) = 35   *I'm guessing they didn't give you sales for the year or else I would divide by 365 but since you mentioned operating cycle I'm assuming thats the sales number you were given.  So you want to divide the sales by 50 and then times it by the 35.  Should give you the average AR.  Inventory - I really don't remember having to calculate this so I'm just thinking logically here.  You should be able to take COGS divide by the days in the period then times it by In Invetory.  So = (COGS/Operating Cycle)* In Inventory = (COGS/50)*15  Accounts Payable....man, I'm afraid to drive you in the wrong direction on this one.  Avg Accounts Payable/(COGS/Operating Cycle) = 40  Plug in COGS, divide by the operating cycle, 50 then times by 40, the days vendor credit. Welcome to the world of personal finance.  IMO, you are heading for trouble. To answer your question, the APR is the annual percentage rate, or what you pay to borrow money from the CC issuer.  For example, if you charge $100, and the bill comes, and you pay $100 on or before the due date you pay nothing.  If you pay the minimum payment, which would be around $15, you would then borrow $85 (100-15) and pay interest on that amount.  The next month's balance would be 85 + any new charges + interest.  The interest in this case can be estimated as follows:  85*.199/12 = 1.41. For your information that is a very high interest rate especially given the current market for borrowed money.  Many people become saddled with debilitating debt starting off just like you are planning.  If we were friends, I would implore you not to get a CC, instead save up and pay for things with cash. The exact percentages depend on many things, not just location. For example, everyone needs food.  If you have a low income, the percentage of your income spent on food would be much higher than for someone that has a high income. Any budgeting guidelines that you find are just a starting point.  You need to look at your own income and expenses and come up with your own spending plan. Start by listing all of the necessities that you have to spend on.  For example, your basic necessities might be: Fund those categories, and any other fixed expenses that you have.  Whatever you have left is available for other things, such as: and anything else that you can think of to spend money on.  If you can save money on some of the necessities above, it will free up money on the discretionary categories below.   Because your income and priorities are different than everyone else, your budget will be different than everyone else, too.  If you are new to budgeting, you might find that the right budgeting software can make the task much easier.  YNAB, EveryDollar, or Mvelopes are three popular choices. Total income - mandatory spending (ie bills) = discretionary income.  Make a budget and calculate how much discretionary income you have each pay period. Save some fraction of your discretionary income towards this purchase. Pull the trigger when you have enough saved.  By thinking this way, you ensure that the PS is robbing from movies, dining out, booze, etc instead of taking from rent money or the electric bill. Do not use debt to make this purchase. It would be wise to put off this purchase until you have a solid emergency cash reserve that can sustain you if life throws you a curve ball. You should also make sure to eliminate any bad debt, like credit card debt, before splurging on a new gaming console.