Reallocation Methods
There are two ways of calculating what the new daily budget should be: evenly distributed or backloaded.
Even distribution
This method simply figures out how much the budget remains for the month and how many days remain, then divides the former by the latter.
Back-Loaded Reallocation
In this method, a larger portion of the budget is kept for the end of the month. If you know you’ll be running a big promotion toward the end of the budget period, this can be a good method to preserve the budget for a time when you expect your ads to perform better in terms of key metrics like CPA or ROAS.
You can read more about how this script can help you in this blog post.
Front-Loaded Reallocation
In this example, we have a month that is 30 days and a budget of $100 for that month. We will assume in this example that you spend the full amount of the daily budget every day. Here’s what budgets the script will set:
Day 1.0 of 30.0, new budget 6.451612903225806, cost so far 0.0
Day 2.0 of 30.0, new budget 6.236559139784946, cost so far 6.451612903225806
Day 3.0 of 30.0, new budget 6.021505376344086, cost so far 12.688172043010752
Day 4.0 of 30.0, new budget 5.806451612903225, cost so far 18.70967741935484
Day 5.0 of 30.0, new budget 5.591397849462366, cost so far 24.516129032258064
Day 6.0 of 30.0, new budget 5.376344086021505, cost so far 30.107526881720432
Day 7.0 of 30.0, new budget 5.161290322580645, cost so far 35.483870967741936
Day 8.0 of 30.0, new budget 4.946236559139785, cost so far 40.645161290322584
Day 9.0 of 30.0, new budget 4.731182795698925, cost so far 45.59139784946237
Day 10.0 of 30.0, new budget 4.516129032258064, cost so far 50.322580645161295
Day 11.0 of 30.0, new budget 4.301075268817204, cost so far 54.83870967741936
Day 12.0 of 30.0, new budget 4.086021505376344, cost so far 59.13978494623656
Day 13.0 of 30.0, new budget 3.870967741935484, cost so far 63.225806451612904
Day 14.0 of 30.0, new budget 3.655913978494624, cost so far 67.09677419354838
Day 15.0 of 30.0, new budget 3.440860215053764, cost so far 70.75268817204301
Day 16.0 of 30.0, new budget 3.225806451612904, cost so far 74.19354838709677
Day 17.0 of 30.0, new budget 3.0107526881720448, cost so far 77.41935483870967
Day 18.0 of 30.0, new budget 2.795698924731184, cost so far 80.43010752688171
Day 19.0 of 30.0, new budget 2.5806451612903234, cost so far 83.2258064516129
Day 20.0 of 30.0, new budget 2.365591397849464, cost so far 85.80645161290322
Day 21.0 of 30.0, new budget 2.1505376344086047, cost so far 88.17204301075267
Day 22.0 of 30.0, new budget 1.9354838709677438, cost so far 90.32258064516128
Day 23.0 of 30.0, new budget 1.7204301075268833, cost so far 92.25806451612902
Day 24.0 of 30.0, new budget 1.5053763440860237, cost so far 93.9784946236559
Day 25.0 of 30.0, new budget 1.2903225806451653, cost so far 95.48387096774192
Day 26.0 of 30.0, new budget 1.0752688172043037, cost so far 96.77419354838709
Day 27.0 of 30.0, new budget 0.860215053763443, cost so far 97.84946236559139
Day 28.0 of 30.0, new budget 0.6451612903225836, cost so far 98.70967741935483
Day 29.0 of 30.0, new budget 0.43010752688172715, cost so far 99.35483870967741
Day 30.0 of 30.0, new budget 0.21505376344086358, cost so far 99.78494623655914
Day 31.0 of 30.0, new budget 0.0, cost so far 100.0
Back-Loaded Reallocation
In this example, we have a month that is 30 days and a budget of $100 for that month. We will assume in this example that you spend the full amount of the daily budget every day. Here’s what budgets the script will set:
Day 1.0 of 30.0, new budget 1.694915254237288, cost so far 0.0
Day 2.0 of 30.0, new budget 1.7246506095747844, cost so far 1.694915254237288
Day 3.0 of 30.0, new budget 1.7560078933852352, cost so far 3.4195658638120725
Day 4.0 of 30.0, new budget 1.78914011778873, cost so far 5.1755737571973075
Day 5.0 of 30.0, new budget 1.8242212965689013, cost so far 6.964713874986037
Day 6.0 of 30.0, new budget 1.8614503026213278, cost so far 8.788935171554938
Day 7.0 of 30.0, new budget 1.9010556282090156, cost so far 10.650385474176266
Day 8.0 of 30.0, new budget 1.9433013088358826, cost so far 12.551441102385281
Day 9.0 of 30.0, new budget 1.9884943625297402, cost so far 14.494742411221164
Day 10.0 of 30.0, new budget 2.036994225030466, cost so far 16.483236773750903
Day 11.0 of 30.0, new budget 2.089224846185093, cost so far 18.52023099878137
Day 12.0 of 30.0, new budget 2.145690382568474, cost so far 20.60945584496646
Day 13.0 of 30.0, new budget 2.2069958220704304, cost so far 22.755146227534937
Day 14.0 of 30.0, new budget 2.2738744833452915, cost so far 24.96214204960537
Day 15.0 of 30.0, new budget 2.347225273130624, cost so far 27.23601653295066
Day 16.0 of 30.0, new budget 2.42816407565237, cost so far 29.583241806081283
Day 17.0 of 30.0, new budget 2.518096078454309, cost so far 32.01140588173365
Day 18.0 of 30.0, new budget 2.6188199215924817, cost so far 34.52950196018796
Day 19.0 of 30.0, new budget 2.732681657313894, cost so far 37.14832188178044
Day 20.0 of 30.0, new budget 2.862809355281222, cost so far 39.88100353909434
Day 21.0 of 30.0, new budget 3.0134835318749706, cost so far 42.74381289437556
Day 22.0 of 30.0, new budget 3.1907472690440866, cost so far 45.75729642625053
Day 23.0 of 30.0, new budget 3.4034637536470256, cost so far 48.948043695294615
Day 24.0 of 30.0, new budget 3.66526865777372, cost so far 52.35150744894164
Day 25.0 of 30.0, new budget 3.9984748993895125, cost so far 56.01677610671536
Day 26.0 of 30.0, new budget 4.442749888210569, cost so far 60.015251006104876
Day 27.0 of 30.0, new budget 5.077428443669222, cost so far 64.45800089431545
Day 28.0 of 30.0, new budget 6.092914132403067, cost so far 69.53542933798467
Day 29.0 of 30.0, new budget 8.123885509870755, cost so far 75.62834347038773
Day 30.0 of 30.0, new budget 16.247771019741506, cost so far 83.7522289802585
Day 31.0 of 30.0, new budget 0.0, cost so far 100.0