How to plan a trip budget and a monthly budget, step by step

Guide · Updated 2026-11-10

Work out what a trip or project costs and how much to save each month, then turn your pay and bills into one monthly budget that shows what you can save. A plain guide to the budget calculator.

Open the Budget planner Free, in your browser, nothing uploaded.

A budget tells you where your money goes before it goes there. The budget planner does two jobs. It works out what a trip, a home project or a big purchase will cost and how much to save for it each month. It also turns your pay and regular bills into one monthly budget that shows what is left to save. Once you have your monthly figure, a bill calendar helps you keep each bill on its due date, and a loan payoff planner shows what extra payments would do to a loan.

What it is

Two ideas sit behind the tool.

The first is the target. The money you still need is the total cost, plus a cushion for surprises, minus what you have already saved. That gap is then shared out over the months you have left. If a trip totals 1,725, you have 400 saved and you have 10 months, the gap is 1,325, and 1,325 ÷ 10 = 132.50 a month.

The cushion is added before the division. Prices rise and things go wrong, so the tool adds a percentage to the total. Ten to twenty percent is a sensible range.

The second idea is the monthly budget. Every amount has to be turned into a monthly figure first, because a weekly bill and a yearly bill cannot be added together until they match:

• weekly amount × 52 ÷ 12 = monthly amount
• yearly amount ÷ 12 = monthly amount

So a transport cost of 20 a week is about 86.67 a month, and a yearly insurance bill of 600 is 50 a month. What is left after all the costs is what you can save. Divide that by your take-home pay and you have your saving rate.

Savings growth works on regular deposits. You put in a fixed amount at the end of each month. The account pays an annual rate, so the monthly rate is that rate divided by 12, and each deposit earns interest for the months it sits there.

How to use it

1. Choose the tab. Trip or project is for a one-off goal. Monthly budget is for your regular money.
2. For a goal, pick a starting list such as Trip or Big purchase, then type an amount beside each cost. Leave a cost empty if it does not apply to you.
3. Set the surprise cushion, enter what you have already saved, and choose the month you want the money ready by.
4. For the monthly budget, add each source of income and say how often it arrives. Then add each cost with its own frequency, and mark it as a Need or a Want.
5. Read the results: what is left to save, the bills that are not monthly, and how your savings grow at the rate you chose.
6. Change one number at a time, such as cutting wants by 20%, to see its effect.

A worked example

Ana plans a six-night trip. The costs are flights 420, hotel 570 (6 nights at 95), food 300, activities 150 and travel insurance 60. The total is 1,500. A 15% cushion adds 225, so the target is 1,725. Ana has 400 saved and wants the money ready in 10 months.

• Still to save: 1,725 − 400 = 1,325
• Per month: 1,325 ÷ 10 = 132.50
• Per week: 1,325 ÷ (10 × 52 ÷ 12) = 30.58

For the monthly budget, Ana’s take-home pay is 2,800 a month. The costs are rent 950 a month, groceries 75 a week (325 a month), transport 20 a week (86.67), phone 25, streaming 15, car insurance 600 a year (50), electricity and water 140, and eating out 40 a week (173.33). The total going out is 1,765 a month. That leaves 2,800 − 1,765 = 1,035 a month, a saving rate of 37%.

Ana marks streaming and eating out as wants. Cutting them by 20% frees 188.33 × 20% = 37.67 a month, or about 452 a year.

Ana decides to save 300 of the 1,035 a month at 4% a year. After 5 years (60 deposits of 300, which is 18,000 of her own money), the pot is about 19,890. For an emergency fund of 9,000, the same 300 a month at 4% reaches the goal in 29 months (the goal box starts from zero).

Where it is used

• Households planning a holiday, school fees, a car replacement or a wedding.
• People with irregular pay, who can enter a typical low month as their income so that a quiet month does not catch them out.
• Small home projects, such as a repair or a new kitchen, where the surprise cushion matters most.
• Anyone with yearly bills, who can use the “set aside” section to save a little each month for insurance or subscriptions.

Common mistakes

1. Using pay before tax. Enter the amount that actually reaches your account. Otherwise every saving figure looks bigger than it is.
2. Forgetting yearly and quarterly bills. They vanish from memory until they are due. Enter them at their real frequency, and use the set-aside figure so the money is ready.
3. Leaving out the surprise cushion. A plan with no cushion runs short at the first price rise. Use 10 to 20%.
4. Treating the growth rate as a promise. Savings rates change, and investments can fall. Set the rate to 0% to see only what you put in.
5. Calling a want a need. Be honest when you mark them. The 50/30/20 split is only a guide, so compare it with your own situation.

Questions people ask

Is 50/30/20 the right split? It is a popular rule of thumb: about half of take-home pay on needs, 30% on wants and 20% on savings or paying off debt. Treat it as a starting point, because housing and transport costs differ a great deal from place to place.

Why does my bank balance look different from the monthly total? Weekly and yearly costs are spread evenly across the months. A month with a big bill will look different from the average, so compare totals over a full year.